Moved Drawbeam part to the Postscript header file.
Fixed a bug: When several extnodes were defined, these nodes couldn't be use together with a compname.
Access last node both with 'N' and its number.
Added a new component \optsource
Added documentation for \optsource.
Fixed implementation of \optsource.
Updated version number and date.
Added value 'firstcomp' to 'beamalign' parameter.
Modified \optsource to use 'beamalign' if available, default alignment was changed to 'relative'.
Added testcases for beamalign=firstcomp.
Added testcases for different beam alignment with \optsource.
Updated version and date.
Merge remote-tracking branch 'origin/master' into arbifc

Conflicts:
	pst-optexp.dtx
	pst-optexp.ins