Make the kqueue monitor to monitor changes in directories too.

Fixes #174

Implement file monitoring with kqueue FreeBSD / macOS.

This implementation is incomplete and does not deal well with deletion
/ renaming.

Rework encoding handling for multi-byte files. Add a test and fix a bug
when copying from a utf-16 file.

Fix build on travis mac os version

Switch from deprecated QRegExp to QRegularExpression

Add automatic support for UTF16.

Fix and end of line bug when a line is extended on a block (256) boundary.

Fix a crash when a big file is updated with partial lines.

Initial implementation of the encoding speculator.

Implement a polling timer in WatchTower (Windows).

Update unit test configuration for Windows.

Fix non-display of marks when no search is active.

CompressedLineStorage now supports >4GB files.

Add caching of the position in CompressedLineStorage.

Now share the indexing data between the two threads.

Compression is disabled.

Complete initial implementation of memory compression.

Implement compression of the memory for the index.

Refactor the LinePositionArray and add tests.

Optimise searches when there is a lot of matches.

Add a perf test for searches.

Correct following a file in a non-existant directory.

Fix the WatchTowerDriver to re-add new files.

Add a temporary config.h and make CMake recognise c++11 compiler support.

LogData now only register files once with the FileWatcher.

Cleanup directories when they are not watched.