Draw complete background for the selected item.
Calculate the size of a large icon more correctly (including multiline
labels).

- TB_INSERTBUTTONW was not as functional as the 'A' version. They now
  match.

default but cy is CW_USEDEFAULT.

trailing space which it should only do for left-justified text.
Also tighten up some comments.

windows.

report mode.

flag is set.

Note that this now highlights weaknesses in the label measuring code
etc. which cannot correctly handle multiline labels.

Convert all msvcrt locks over to use _lock and _unlock.
Explicitly make msvcrt compile with multithreaded option.
Fix flag handling in _sopen. Add W->A call for new _swopen.

- Implement ordinals 155, 350, 351, 352, 418, 436.
- Fake implementation of SHGetInverseCMAP.
- Stub ordinal 209.
- Fix definition of ordinal 7.
- Implement SHGetThreadRef and SHSetThreadRef.

old-style config.cache.

Added make rules for building and running C unit tests.

- made changes to the precompiler directives to check for specific
  features instead of checking for the environment version.

- Fix brainfade in previous delta
- Move ellipsification results to static memory; they are going to
  have to be referenced inside NextLineW and the arg list is too big
  already.
- Add the missing ellipsification result (len_under) to simplify coding.
- Slight correction to prefix tracking for when there are several
  underlined characters on a single line (DT_EXPANDTABS only).
- Allocate and free the temporary copy required for DT_MODIFYSTRING
  rather than using a fixed size stack array.
- Introduce lastline into the main loop; it simplifies the code and we
  are going to need it.