ADD: SqliteSchemaDumper + SqliteSchemaDumperTest

Added SqliteSchemaDumper class + SqliteSchemaDumper tests
SchemaDumper - Code style cleanup

 - Also deleted VS2012 solution file as it is exactly the same as the
   VS2010 solution file.
Merge pull request #383 from dsoronda/master
csproj automerge fix

Automerge messed up the csproj file. Removed entries that are not there
anymore.
Add Travis CI icon for Mono build
Update README.textile
Migrations with tags problem. Closes #403

 - Migrations with tags should not be applied if no tags to match were
   passed in to the Migration runner.
Added tests for PostgresGenerator

 - Create Primary Key constraint