Common-opencl: Change an ambiguous function name.
Re-enable vector width 3. Most problems with it not working is because
our LWS/GWS enumerations pick unsuitable figures for that width.
OpenCL formats: Use shared functions.
RAKP: Use lower default KPC so weak devices don't die on us.
RAKP OpenCL tweaks.
Try to fix a regression on 13.4 Catalyst driver (revert performance to 13.1 situation).

 From:
 Local worksize (LWS) 64, global worksize (GWS) 32768
 Benchmarking: sha512crypt-opencl, crypt(3) $6$ (rounds=5000) [SHA512 OpenCL]... DONE
 Raw:    8467 c/s real, 819200 c/s virtual

To:
 Local worksize (LWS) 64, global worksize (GWS) 32768
 Benchmarking: sha512crypt-opencl, crypt(3) $6$ (rounds=5000) [SHA512 OpenCL]... DONE
 Raw:    13484 c/s real, 655360 c/s virtual
common-opencl.c: Make it use its own helper functions w/ available,
plus a bunch of whitespace fixes.
RAKP OpenCL: Implement proper GWS tuning.
OpenCL formats: Use size_t instead of int in a bunch of places because
of problems where eg. a GWS of 32M x buffer size of 64 ends up in 2G
which doesn't fit in a signed int.
Duration limit tweaks to some OpenCL formats.
Add opencl_get_vector_width(device_id, size) function to common-opencl.[ch]
and have all vector-capable formats use it.
New OpenCL LWS/GWS enumeration scheme:
1. Enumerate GWS using *LWS == NULL.
2. Enumerate LWS using the now known GWS.

Affected formats: NTLMv2, RAR, krb5pa-md5, krb5pa-sha1, wpapsk, rakp,
mysql-sha1 and office formats.