Change documentation (issue #7)
This version introduces multiple enhancements:

All documentation changed to english language, and written missing documentation.
Also changed some code convention in the same files.
sql_class changed to abstract abstractSql_class

Details of additions/deletions below:
--------------------------------------------------------------

Added:      /BLUE_FRAMEWORK/packages/db/abstractSql_class.php
            -- Modified --
               changed code conventions
               added documentation
               changed name form sql_class to abstractSql_class
               added some variables and methods common to all methods

Deleted:    /BLUE_FRAMEWORK/packages/db/sql_class.php

Modified:   /BLUE_FRAMEWORK/packages/db/fb_class.php
            -- Modified --
               changed code conventions
               added documentation
            -- Added --
               required abstract class definition

Modified:   /BLUE_FRAMEWORK/packages/db/mssql_class.php
            -- Modified --
               changed code conventions
               added documentation
            -- Added --
               required abstract class definition

Modified:   /BLUE_FRAMEWORK/packages/db/queryBuilder_class.php
            -- Modified --
               changed code conventions
               added documentation

Modified:   /BLUE_FRAMEWORK/packages/db/xmlDB_class.php
            -- Modified --
               changed code conventions
               added documentation
            -- Added --
               required abstract class definition

Modified:   /BLUE_FRAMEWORK/packages/db/mysql_class.php
            -- Modified --
               changed code conventions
               added documentation
            -- Added --
               required abstract class definition