Merge remote-tracking branch 'origin/master' into osx
Merge branch 'master' into osx

Conflicts:
	sample/makefile
added an ebuild script for Gentoo
removed Tx and Rx logging from ebuild by default
fixed C++ makefile
replaced calls to sleep() with usleep() for Ubuntu 13.04 compatibility??
replaced call to sleep() with usleep() in xbee.c
fixed 'assignment from incompatible pointer type' warning
fixed 'unused variables' warning
added the remaining Gentoo package support files
fixed 11.uart_test sample for Ubuntu 13.04.....
Merge branch 'master' into osx
fixed buildall script
fixed xbee1/13.lxb2lxb_client sample makefile
Merge branch 'master' into osx
fixed type mismatch in xbee2/8.forced_io sample
Merge branch 'master' into osx
implemented file locking on Linux, to prevent multiple applications accessing the same XBee
removed unnecessary (and wrong) cast
samples are no longer executed as part of the default 'make'