Revert "do not unlink lockfiles (closes #703)"

This reverts commit 9ffe8907dd8be17501601c5af53c73fd0f25ee04.
make_lockfile: check ino and dev fields for lock file (refs #703)
apply special feedTree styles only to main UI feedtree, fix feedParam and filterParam screwing with tree node layout
hide floatingTitle when first batch of headlines is received
add some inset shadow on container elements
update: do not explicitly fclose lockfile before unlinking (refs #703)
info/warning/error: use inset shadows
fix calculation of feed counts in pref-feeds editor
Merge remote-tracking branch 'upstream/master'