Weird behavior was observed during fwrite when files were only opened
with "a". fwrite did not write the expected number of bytes (probably
augumented things with a \n or \r). This caused serious problems parsing
the dumped files in matlab. Forcing a binary fopen option fixed things.

VS throws errors in several locations about ambigious type casting.
Fixed by removing the ambiguities and casting things to double.

This fixes a segfault that happened when no electrode was selected on a spike detector (e.g., with no electrodes added); getSelectedItemIndex returns -1 in this case, which was causing an array bounds segfault in drawElectrodeButtons.