Merged command server support.

Bugfix for Linux - set lineEndTransparent onlt on Windows. Set #lineEndTransparent in HGCommandServer>>start only on Windows, otherwise command server terminates prematurely on Linux. No clue why.

Raise priority of stderr parser proces when spawning command (not using command server). This is mainly workaround for Windows where command server cannot be used. This increases the chance that stderr parser finishes before stdout and then any error written to stderr will be signalled before stdout parser finishes by error because of no data. Certainly a hack.

Fixes for command server. Do not use command server on Windows - readWait is broken on Windows. Also, do not terminate readerwriter process when a command is executing - the command processing may wait for user input.

Tracing and debugging turned off by default.

HGCommandServer>>execute: refactored & hopefully fixed. Now it does not use worket thread read command status. All HGTests pass.

Terminate command server's after some time of inactivity (currently 1min), The #execute: method automatically starts a server if not running. This reduces a number of running servers and dispatchers and thus save resources.

Remover repository instvar deom command server to allow for GC.

Fix in HGRepository>>#branches when using command server. When using command server and there is no output, nothing is ever sent to the $o channel and thus output parser is not even run.

Fixed bug in spawning workers. Fixes push/pull tests, breaks test_commit_02a & test_commit_04a. Also, there is a memory leak (reader/writer processes are not cleaned up)