SQL: many keywords and functions

extended list of keywords and functions.
MySQL 5 syntax
Hightlight returns keyword for protobug rpc services
New: add more functions of T-SQL
Merge remote-tracking branch 'isagalaev/master' into sql_improvements
Merge remote-tracking branch 'neor-ru/patch-4' into sql_improvements

Conflicts:
	src/languages/sql.js
Bye bye aggregate
Use beginKeywords, drop extra relevance for ilike keyword
Respect new contributors
Unique and order SQL keywords
Merge remote-tracking branch 'origin/master' into sql_improvements
Merge remote-tracking branch 'origin/master' into sql_improvements
Merge remote-tracking branch 'origin/master' into sql_improvements
Name
Merge pull request #393 from Sannis/sql_improvements

SQL improvements