Remove use of PATH_MAX

Remove use of PATH_MAX

Instead of using statically allocated char arrays, allocate the memory for the
paths dynamically. This removes the use of PATH_MAX. PATH_MAX is not part of C99
and also seems to be incorrect on some systems that provide it (In terms of
being defined to a value smaller than the maximal path length a system
supports).

Signed-off-by: Tobias Grosser <tobias@grosser.es>
Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>