only enable RESTRICT fk constraint tests for supporting dialects

MSSQL doesn't support a RESTRICT fk constraint, so we need a way
to conditionally disable these tests. This change adds an extra
section to dialect.supports indicating support for RESTRICT
constraints. Also changed some cases where RESTRICT wasn't being
explicitly tested but used to test the ability to simply use
constraints (query-interface.test.js)
Merge pull request #2605 from mbroadst/restrict-support

only enable RESTRICT fk constraint tests for supporting dialects
Initial setup for ms sql server support
Add showTablesQuery / dropTableQuery
Add first steps for createTableQuery
fix dropTableQuery
updates to mssql dialect
Removed super verbose logging
"query-interface describeTable" test now passes
All but the last test pass in Query Interface
Started refactor of mssql dialect
QueryInterface passes with refactor
More separation and a template file for abstract
Destroyed the Select statement, now rebuilding
Fixed bug in lib/model.js deleting clauses
fixed identity column with Insert
Partial fix for where clause, still issues
Alias Test passes
Fixes for lib/instance passing where clause
Fixes to where clause generation