makeStaticLoader: Implement --fixdir option

Currently when running this maintenance script it outputs
the full path to the i18n file. This was done that way because
of .docs/generate.sh (which pipes it to php through stdin).

This however means that currently the output is not suitable
for pasting into demo and test index files (as the path should
be relative for those).

The --fixdir option will function as toggle between a fixed
path to the directory on disk, or a dynamic resolution at
run-time. The default is the latter. generate.sh passes --fixdir.

Change-Id: Idebca553587aaff9b31255d884461f4a51e70afd
makeStaticLoader: Fix trailing slash

Change-Id: Ic2b14aae725769957c203de7f4ce820fc2ee110f