Can't deploy any app that uses Webkit2

[freakboy3742]

Linuxdeploy is unable to deploy a GTK app that uses Webkit2.

AFAICT, this is due to the fact that Webkit2 uses subprocesses to manage rendering and network behavior, and requires that those executables are in very specific locations on disk that are fixed at the time of compilation. Linuxdeploy (a) tries to put all executables in the bin directory, which breaks the path that Webkit2 expects to use, and (b) the path used by Webkit2 changes as a result of being relocated by linuxdeploy.

There was a prototype patch in #37; however, that patch involved running sed over executables to fix the path, which... doesn't seem like a good approach. YMMV, but the patch didn't work for me.