move static table for byte wise select

refactor determine bits per value
add extern variables to documentation

add module thread to include gt_jobs in the documentation.

closes #37
add static table for byte wise popcount to core/api
Merge pull request #40 from Garonenur/dw

add extern variables to documentation
Implemented GtResetSourceStream class, implemented small functional test with gt gff3
Added D. Standage to contributors
Merge pull request #42 from standage/master

Implemented GtResetSourceStream class
Merge pull request #43 from Garonenur/bytebits

Bytebits