Fix the GTK2 build

Apparently gdkkeysyms.h isn't dragged in by other headers.
Revert "Add HTTPS-Everywhere support"

This reverts commit d02f600a4a82b912c4f26beecbcee8d3ddc148d5.

Not fast enough and incomplete anyways.
Don't replace @PREFIX@ in *.in files twice
Only change mode of python and shell example scripts
Merge remote-tracking branch 'gh/nmeum/next' into next

* gh/nmeum/next:
  Only change mode of python and shell example scripts
  Don't replace @PREFIX@ in *.in files twice