first set of db->json translations for mysql integer types

Reviewers: abahouth

CC: egor, esayle, abahouth, mhalverson, SQLWILL, kali

Differential Revision: http://phabulous.newokl.com/D24
vertica integer and binary types + tests
mysql date types
break out into db-specific tests
break out mysql tests
vertica WIP
finished first pass at vertica types

CC: egor, esayle, abahouth, mhalverson, SQLWILL, kali

Differential Revision: http://phabulous.newokl.com/D29
reorganize comments for clarity
sql server type mappings
Fix comments
first iteration on refactoring

CC: egor, esayle, abahouth, mhalverson, SQLWILL, kali

Differential Revision: http://phabulous.newokl.com/D31
checkpointing
add support for BIT, ENUM, and SET
fix min/max bug
fix min/max bug
add type translator abstraction
wider-than? predicate with mixed type support
reverse type mapping and column width predicates
checkpoint
catch some missing type mappings