Add ofThread argument for tryJoin time.
Change sleep time to long, to match Poco methods.
ofThread overhaul, documentation. Example fixes.
Merge branch 'master' of github.com:bakercp/openFrameworks into enhancement-ofThread-join

Conflicts:
	examples/utils/threadExample/src/main.cpp
	examples/utils/threadExample/src/ofApp.cpp
	examples/utils/threadExample/src/ofApp.h
Const corrections, further docs and variable name changes.
Atomic, private member variables.
Cleanup.
Cleanup examples.
Merging changes.
Update documentation to proposed style.
Undoing cleanup.
Continued unclean up.
Merge branch 'master' of git://github.com/openframeworks/openFrameworks into enhancement-ofThread-join
Attempting to match oF style.
Merge pull request #2505 from bakercp/enhancement-ofThread-join

Fix for #2504 (and more, see below)