Upgrade php55-pthreads to 0.0.44 and php55-http 1.7.6

Hi,

I just trying to setup my env with php55 and the pthreads and http module fails, i upgraded the versions to the last stable of each library and work it, so this is the pr.

From 
pthreads 0.0.42(beta) to 0.0.44(beta)
pecl_http 1.7.4(stable) to 1.7.6(stable)


Regards and thanks for you excelent job