Maintenance release

Fix merge error in 0.55

Blob support, multiple new datatypes and small fixes

- ddl2cpp:
  - add multiple data types
  - option to not camel-case SQL names in C++
  - allow digits in names
- Allow tuples to be passed to insert_set
- Fix some static_assert messages

Use date/date.h (as in date 2.4)

Small fixes

Trim function (Juan Dent)

Hopefully fixed compile issues with VC++

support for date/datetime/timestamp types added for ppgen

Fix without_table_check for alias expressions
several automated edits using clang-format

Silence a couple of warnings (clang-tidy and gcc-6.x)

Maintenance release:

  - compile with MSVC 2017 again
	- remove some clang warnings
  - Fixed incorrect usage of string::find

Add get default transaction isolation level function (thanks volka)

Appease MSVC 2015 Update 3