- since 1612, FOAM_INST_DIR and foamInstDir longer have any
special meanings when sourcing the bashrc or cshrc files.
Thus no need for special treatment in any of the dispatch wrappers.
Retained FOAM_INST_DIR as (unexported) variable in etc/bashrc,
just in case people are using patched versions of etc/bashrc
as part of their installation.
ENH: relax prefix restrictions on foamCreateVideo (issue #904)
- shift the implicit '.' to be part of the default prefix. This allows
things like "-image myimages_00" to work as might be expected.