Move database setup guide inside the installation.

doc/install/database_mysql.md

 ## Note
-We do not recommend using MySQL due to various issues. For example, case [(in)sensitivity](https://dev.mysql.com/doc/refman/5.0/en/case-sensitivity.html) and [problems](http://bugs.mysql.com/bug.php?id=65830) that [suggested](http://bugs.mysql.com/bug.php?id=50909) [fixes](http://bugs.mysql.com/bug.php?id=65830) [have](http://bugs.mysql.com/bug.php?id=63164) .
+We do not recommend using MySQL due to various issues. For example, case [(in)sensitivity](https://dev.mysql.com/doc/refman/5.0/en/case-sensitivity.html) and [problems](http://bugs.mysql.com/bug.php?id=65830) that [suggested](http://bugs.mysql.com/bug.php?id=50909) [fixes](http://bugs.mysql.com/bug.php?id=65830) [have](http://bugs.mysql.com/bug.php?id=63164).
 ## MySQL

doc/install/databases.md

-# Setup Database
-
-GitLab supports the following databases:
-
-* PostgreSQL (preferred)
-* [MySQL](doc/install/database_mysql.md)
-
-## PostgreSQL
-
-    # Install the database packages
-    sudo apt-get install -y postgresql-9.1 postgresql-client libpq-dev
-
-    # Login to PostgreSQL
-    sudo -u postgres psql -d template1
-
-    # Create a user for GitLab.
-    template1=# CREATE USER git;
-
-    # Create the GitLab production database & grant all privileges on database
-    template1=# CREATE DATABASE gitlabhq_production OWNER git;
-
-    # Quit the database session
-    template1=# \q
-
-    # Try connecting to the new database with the new user
-    sudo -u git -H psql -d gitlabhq_production
-

doc/install/installation.md

@@ -144,7 +144,25 @@ GitLab Shell is an ssh access and repository management software developed speci
 # 5. Database
-To setup the PostgreSQL/MySQL database and dependencies please see [doc/install/databases.md](doc/install/databases.md).
+We recommend using a PostgreSQL database. For MySQL check [MySQL setup guide](doc/install/database_mysql.md).
+
+    # Install the database packages
+    sudo apt-get install -y postgresql-9.1 postgresql-client libpq-dev
+
+    # Login to PostgreSQL
+    sudo -u postgres psql -d template1
+
+    # Create a user for GitLab.
+    template1=# CREATE USER git;
+
+    # Create the GitLab production database & grant all privileges on database
+    template1=# CREATE DATABASE gitlabhq_production OWNER git;
+
+    # Quit the database session
+    template1=# \q
+
+    # Try connecting to the new database with the new user
+    sudo -u git -H psql -d gitlabhq_production
 # 6. GitLab