Added description support for migrations

Signed-off-by: Michał Zalewski <michal@mzalewski.net>
Merged with upstream/master
Added IVersionMetaDataEx(tended) closes  #295
Choose the least breaking way of implementing this feature
Implemented support for generating table descriptions and column descriptions for Oracle and SqlServer (version 2005 or greater), added unit tests for the newly implemented feature. Also, refactored code by moving FormatSqlEscape method (which was duplicated in multiple classes) in static class FormatHelper.
Renamed IVersionTableMetaDataEx to IVersionTableMetaDataExtended, just to reveal intend better
Added call of MySqlQuoter.QuoteTableName into MySqlProcessor.ReadTableData, integration test.
Merge pull request #435 of NikGovorov/mysql-quote-ver

# By NikGovorov
# Via NikGovorov
* NikGovorov-mysql-quote-ver:
  Added call of MySqlQuoter.QuoteTableName into MySqlProcessor.ReadTableData, integration test.
Removed InvalidOperationException and added license region to ForwardOnlyMigration closes #436
Merge pull request #438 from tommarien/forwardonly-migration-does-not-throw

ForwardOnlyMigration does not throw anymore on down
Added Gemfile to better manage gem dependencies.
Merge pull request #444 from kieranmaine/master

Added Gemfile to better manage gem dependencies.
Specify tab size for Ruby code
Merge pull request #428 from stefan-ojog/master

Added description support for tables and columns on MS Sql Server and Oracle
Environment.Newline fix for sql server 2005 generator tests
set CLS compliance to true
fixed SqlServer2000Processor sql template error
Corrected parameter name from "primaryTableName" to "foreignTableName"
Merge pull request #448 from starpeng/master

fixed SqlServer2000Processor sql template error
Merge pull request #449 from geirsag/master

Corrected parameter name from "primaryTableName" to "foreignTableName"
Merge pull request #447 from lahma/set-ClsCompliant-true

set CLS compliance to true in nant script