Added more MSSQL datepart types
bug fixes during adding implicit cast to sqream
implicit cast of arguments of functions
Merge remote branch 'ghsqppp/master'
support for literal arguments to date functions
Merge remote branch 'origin/master'
implicit cast of QueryExpr (except of Values)
Added 'y' clause
Added missing 'y' clause
implicit cast of QueryExpr (UNION, VALUES)
Merge remote branch 'ghsqppp/master'
make after merge
inference of nullability for outer joins
changes in handling of dates
  in particular, the default template catalog was changed
bug fixes
version changed to 0.5.2
nullability component of a type is not taking into account during implicit cast,
  except a few cases (like UNION) when it is necessary
add uuagc check
add INSTALL doc
fix typo
add support for identity constraint
cast to nullable: bug fixes