added builddir and emudir variables
pass module id and description to module functions to allow them to be used to avoid string/path duplication etc
updated advmame.sh module to use separate build/install directories, the new emudir/builddir variables and other cleanups
rework atari800 to split source/binary and use new variables/parameters
Merge branch 'master' into separate_sources
handle pushd/popd in packages.sh to minimise duplication in modules
removed uneeded pushd/popd from first two modules
remove source folders if they exist - we always do a clean checkout now
move error testing for "required" files to packages.sh - makes it easier for modules to report if something has worked or not
rework basilisk emulator for new build location
create the install destination directory before running install
don't try to remove folder for git pull/clone function
reworked cpc emulator for new build location / system
reworked dgen for new build location / system
create builddir for install function also for the case of files installed from binaries
reworked eduke32 for new build location / system
no need to change directory for unpacking tar - we are in the correct location
reworked fastdosbox for new build location / system
allow modules to return a list of files/directories for copying/installing
rework fbzx for new build location / system (including list of files to install)