last-minute bundling fixes, <3 @SpiKe

• bundle: do not bundle libstdc++, pango, and some remaining X11 stuff on Linux

  • it's a bad idea to bundle libstdc++ as it may conflict in non-obvious manner (like failing on X11 stuff)
  • pango is known to conflict with newer distros
  • no need to bundle libICE and libSM since we expect user to have a working x11 install

• cmake: fix a mistake introduced while revamping bundling code, <3 @SpiKe