Revert "Open config with fewer races and better checks"

This reverts commit 15443a43080233103ef6032a909a3d10b129cf1b. This
change broke a bit more than hoped (several issues with reloading and
the double parse; inotify would only work partially due to the fd being
kept open).

Conflicts:
	src/conky.c
Add error message when literal text is too long

When the literal text in a config exceeds text_buffer_size in length,
the result is other variables being injected in unexpected places. Given
that the situation can be easily detected, issue a warning message.
Improve get_fs_type

This should use the last matching mount entry, and some scenarios
involving symlinks would fail to result in a proper fs type.