libhb: change libhb.a to libhandbrake.a
On linux, there is a problem with some distros that dynamically link
harfbuzz (libhb) to libass.  The name conflicts with our libhb.  So this
changes the library name to resolve the conflict.

It only changes libhb.a.  It does not affect the windows libraries
hb.lib and hb.dll


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6020 b64f7644-9d1e-0410-96f1-a4d463321fa5