Add support for multiple SQL dialects

[roskakori]

trafficstars

Goal: as extension to #73 and AnsiSqlDialect, the following dialects are supported:

ANSI

• Data types: done
• Keywords: http://developer.mimer.se/validator/sql-reserved-words.tml

DB2 (IBM)

• Data types: http://www-01.ibm.com/support/knowledgecenter/SSEPEK_10.0.0/com.ibm.db2z10.doc.intro/src/tpc/db2z_datatypes.dita?lang=en
• Keywords: http://www-01.ibm.com/support/knowledgecenter/SSEPEK_10.0.0/com.ibm.db2z10.doc.sqlref/src/tpc/db2z_reservedwords.dita

PL/SQL (Oracle)

• Data types: http://docs.oracle.com/cd/B28359_01/server.111/b28318/datatype.htm#CNCPT213
• Keywords: http://docs.oracle.com/cd/B19306_01/appdev.102/b14261/reservewords.htm

MySQL / MariaDB

• Data types: http://dev.mysql.com/doc/refman/5.7/en/data-type-overview.html
• Keywords: http://dev.mysql.com/doc/mysqld-version-reference/en/mysqld-version-reference-reservedwords-5-5.html

postgresql

• Data types: TODO
• Keywords: http://www.postgresql.org/docs/8.1/static/sql-keywords-appendix.html

SQLite

• Data types: TODO
• Keywords: https://www.sqlite.org/lang_keywords.html

T/SQL (Microsoft)

• Data types: https://msdn.microsoft.com/en-us/library/ms187752.aspx
• Keywords: https://msdn.microsoft.com/en-us/library/ms189822.aspx

[roskakori]

Please add links to data types and implement as discussed.