Merge pull request #729 from hasufell/mime

fix htm desktop file
Merge pull request #728 from hasufell/master

build system improvements
BUILD: add --with-theme-manager configure option
BUILD: fix quoting issue

\"$@\" got malformed and interpreted by the Makefile
BUILD: don't hardcode the install path in the script
BUILD: use thememan.in instead of Makefile echo
update gitignore
update desktop file
BUILD: update mime and desktop database