E2 log2 fix (sort of)

Workaround for ancient float issue where for example floor( log2(128) )
would return 6, should be 7.

http://www.wiremod.com/forum/bug-reports-archive/30030-floor-7-6-a.html
Merge pull request #223 from ArcticFqx/master

E2 log2 fix (sort of)