* .version: Updated to 2.3.1

	* src/z80/main.c (z80_port =): Added macro based linker and assembler command line support.
	Added copyright header.

	* src/SDCCmain.c: Shifted various functions into SDCCutil.c
	(assemble): Added support for macro based assembler commands.
	(linkEdit): Added support for macro based linker commands.
	(preProcess): Changed the pre-processor to use macros.
	(_setPaths): Added functionality to autodetect the include, lib and bin dir paths.
	(_discoverPaths): Added support for overriding the install directory using the SDCCDIR env variable.

	* device/lib/z80/crt0.s: Added module name for debugging.
	* src/SDCCmain.c (printVersionInfo): Added the build date to the version info.

	* src/SDCChasht.c (hTabDeleteByKey): Fixed delete as it would delete the last item from a bucket even if it wasn't the real one.

	* src/SDCCglue.c: Moved gc_strdup to SDCCutil.c

	* src/Makefile.in: Added SDCCmacro and SDCCutil

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@1303 4a8a32a2-be11-0410-ad9d-d568d2c75423