Updated ICARUS ucf to fix leds

Set the TMP pins to PULLUP so as not to light the HOT led. Disabled the
IDLE led. Also changed I/O from 2.5 to 3.3V since this is what the board
runs at.
Fixed hash rate reporting for ltcminer.py
Add experimental/LX150-SPLIT
Added divide by 0 test to ltcminer.py

Rasorfish has noted a problem, this is an interim change until we find
out why its trying to divide by zero. Also changed default diff from 32
to 2 so we don't throw away work when target is incorrectly set.
Updated python mining scripts

Added check for zero target (seems to be caused by NOT using the -pa
scrypt parameter in the stratum proxy). Added ltcminer-testmode.py for
testing. Replaced leading spaces with tabs to make editing easier in
Notepad++ as it was just way too painful before. YMMV.
Bitstreams
Updated ltcminer.py
New experimental/LX150-EIGHT-A
Update testbenches

Added ifdef SIM to avoid "wrong top" if included in ISE/PlanAhead build
Minor change to salsaengine

Tweaked scheduling and added full scratchpad support
Fix salsa_shift reset in pbkdfengine
auto dev server commit
Merge remote-tracking branch 'upstream/master'