add suport for rar-5.0x

Commits are from file-roller an abit adjusted for engrampa.

rar: show the links correctly
https://git.gnome.org/browse/file-roller/commit/?h=gnome-3-6&id=dd418a2aeb9a3d9b605e5d54c4eba29f5f6dcb4e

rar: add support for rar-5.00
https://git.gnome.org/browse/file-roller/commit/?id=ab9da614aed62145ef951eadbf8ecc827aa17986

rar: fixed some compiler warnings
https://git.gnome.org/browse/file-roller/commit/?id=e25aeb637a398a6ad97c93e2f910c1e4e313d08d

rar: use a more solid way to get the version number
https://git.gnome.org/browse/file-roller/commit/?id=1427ba9245e8e8de8584b4022a2bdbc2e69a7619

rar: make a condition clearer
https://git.gnome.org/browse/file-roller/commit/?id=06fbc9da6ae4740159831507edaff1fa296c15e9

rar: fixed unrar version detection
https://git.gnome.org/browse/file-roller/commit/?id=af69158b7d4800c606498184787b1fcd2d30e8d9

All is test in f18 with rar-4.2 and rar-5.0, both versions are working (extract/compress) correctly with engrampa.

see http://forums.mate-desktop.org/viewtopic.php?f=16&t=2009