[TASK] Fix issues in the db analyser

ext_tables.sql

 CREATE TABLE tx_sgjobs_domain_model_job (
-	path_segment           text                DEFAULT ''    NOT NULL,
-	title                  text                DEFAULT ''    NOT NULL,
+	path_segment           text,
+	title                  text,
 	job_id                 varchar(30)         DEFAULT ''    NOT NULL,
 	attachment             int(11)             DEFAULT '0'   NOT NULL,
-	task                   text                DEFAULT ''    NOT NULL,
-	qualification          text                DEFAULT ''    NOT NULL,
-	alternative_start_date text                DEFAULT ''    NOT NULL,
+	task                   text,
+	qualification          text,
+	alternative_start_date text,
 	start_date             int(11) unsigned    DEFAULT '0'   NOT NULL,
-	location               text                DEFAULT ''    NOT NULL,
-	location_requirements  text                DEFAULT ''    NOT NULL,
-	company                text                DEFAULT ''    NOT NULL,
+	location               text,
+	location_requirements  text,
+	company                text,
 	telecommute_possible   tinyint(4) unsigned DEFAULT '0'   NOT NULL,
 	office_work_possible   tinyint(4) unsigned DEFAULT '1'   NOT NULL,
-	employment_types       text                DEFAULT ''    NOT NULL,
+	employment_types       text,
 	date_posted            int(11) unsigned    DEFAULT '0'   NOT NULL,
 	valid_through          int(11) unsigned    DEFAULT '0'   NOT NULL,
 	salary_currency        varchar(3)          DEFAULT 'EUR' NOT NULL,
 	base_salary            varchar(15)         DEFAULT ''    NOT NULL,
 	max_salary             varchar(15)         DEFAULT ''    NOT NULL,
 	salary_unit            varchar(5)          DEFAULT ''    NOT NULL,
-	description            text                DEFAULT ''    NOT NULL,
+	description            text,
 	department             int(11)             DEFAULT '0'   NOT NULL,
 	experience_level       varchar(255)        DEFAULT '0'   NOT NULL,
 	contact                int(11) unsigned    DEFAULT '0'   NOT NULL,
@@ -31,11 +31,11 @@ CREATE TABLE tx_sgjobs_domain_model_job (
 );
 
 CREATE TABLE tx_sgjobs_domain_model_department (
-	title text DEFAULT '' NOT NULL
+	title text
 );
 
 CREATE TABLE tx_sgjobs_domain_model_experience_level (
-	title text DEFAULT '' NOT NULL
+	title text
 );
 
 CREATE TABLE tx_sgjobs_domain_model_company (
@@ -45,9 +45,9 @@ CREATE TABLE tx_sgjobs_domain_model_company (
 	street          varchar(255)     DEFAULT ''  NOT NULL,
 	state           varchar(255)     DEFAULT ''  NOT NULL,
 	country         varchar(255)     DEFAULT ''  NOT NULL,
-	description     text             DEFAULT ''  NOT NULL,
+	description     text,
 	contact         int(11) unsigned DEFAULT '0' NOT NULL,
-	job_id          text             DEFAULT ''  NOT NULL,
+	job_id          text,
 	identifying_url varchar(255)     DEFAULT ''  NOT NULL
 );
 
@@ -66,24 +66,24 @@ CREATE TABLE tx_sgjobs_domain_model_contact (
 );
 
 CREATE TABLE tx_sgjobs_domain_model_job_application (
-	job_id         text                DEFAULT ''  NOT NULL,
+	job_id         text,
 	job            int(11) unsigned    DEFAULT '0' NOT NULL,
-	job_title      text                DEFAULT ''  NOT NULL,
-	company        text                DEFAULT ''  NOT NULL,
+	job_title      text,
+	company        text,
 	gender         varchar(30)         DEFAULT ''  NOT NULL,
-	first_name     text                DEFAULT ''  NOT NULL,
-	last_name      text                DEFAULT ''  NOT NULL,
-	street         text                DEFAULT ''  NOT NULL,
-	city           text                DEFAULT ''  NOT NULL,
+	first_name     text,
+	last_name      text,
+	street         text,
+	city           text,
 	zip            varchar(255)        DEFAULT ''  NOT NULL,
-	country        text                DEFAULT ''  NOT NULL,
-	nationality    text                DEFAULT ''  NOT NULL,
-	education      text                DEFAULT ''  NOT NULL,
-	birth_date     text                DEFAULT ''  NOT NULL,
-	phone          text                DEFAULT ''  NOT NULL,
-	mobile         text                DEFAULT ''  NOT NULL,
-	email          text                DEFAULT ''  NOT NULL,
-	message        text                DEFAULT ''  NOT NULL,
+	country        text,
+	nationality    text,
+	education      text,
+	birth_date     text,
+	phone          text,
+	mobile         text,
+	email          text,
+	message        text,
 	cover_letter   int(11) unsigned    DEFAULT '0' NOT NULL,
 	certificate    int(11) unsigned    DEFAULT '0' NOT NULL,
 	cv             int(11) unsigned    DEFAULT '0' NOT NULL,