File::rename

- Added a rename method to permit safe file writes.
Internationalization

- Fixed the mechanism used to select translations (thanks to Fidel Mato).
Portability

- Detected birth time in struct stat.
Merge branch '2.2.0' of tasktools.org:task into 2.2.0
Code Cleanup

- Rename the class CmdStatistics to CmdStats for consistency
  because 'stats' is the command.

Signed-off-by: Paul Beckingham <paul@beckingham.net>
Bug

- Hyphenation is not needed when words are split with commas.
- Unit test added.
C -> C++

- Integrated wcwidth6.c more into text.cpp.
- Moved wcwidth6.c to wcwidth6.cpp, to cure some strange build issue.
Spanish (es-ES) Localization

- The latest translation update from Fidel Mato.
Feature

- Bash now completes "rc:" with file names and
  "rc.data.location:" with folder names.
Spanish (es-ES) Localization

- The latest translation update from Fidel Mato.
Feature #1124

- Added '_show' command to generate a machine-readable configuration settings
  list for use by third-party software (thanks to Jake Bell).
Build System

- Removed code that searches for the pthreads and Lua51 libraries.
L10N

- Corrections, new strings.

Signed-off-by: Paul Beckingham <paul@beckingham.net>
Bug #1117

Fixed some other merge issues with the sorting order of equally timestamped
entries in undo.data (see #1104).

1. The fact that both files can begin with equal timestamps but different
   modifications has not been taken into account.

2. Besides the fact that the relative order within the same data file must
   be preservered as introduced before, we also need a unique order for entries
   of different data files so that each machine comes to the same merge result.
   This has now been achieved by taking the UUIDs into account as soon as the
   timestamps are equal.
Merge bug

Hopefully found the ultimate cause of duplicated (completed) tasks.

The corresponding test case

 1. does not rely on the fact that there are modifications with equal
    timestamps and
 2. is a LOT simpler than the other ones.
Feature #1099

- Added Feature #1099, which supports the 'color.uda.<uda-name>' color rule
  (thanks to Florian Hollerweger).
Feature #1061

- Added Feature #1061, which allows the 'columns' command to use a search
  string for the column name (thanks to Uli Martens).
Feature #1039

- Added Feature #1039, which adds new date shortcuts, 'socm' and 'eocm',
  meaning start and end of current month (thanks to Thomas Sullivan,
  Louis-Claude Canon).
Bug #1123

- Fixed bug #1123, which caused the undo of a 'log' command to corrupt the data
  file (thanks to Tim None).
L10N

- Placeholder for date range checking.