Merge pull request #752 from magcius/remove-bootleg-events

X11Utils: Remove unneeded SendButtonEvent / SendKeyEvent utilities
X11Utils: Don't depend on wx

We want to have two build targets: Main and MainNoGUI, and this code
will be linked against in both cases, so the ifdef isn't enough for
this case.

Just append to a vector of strings, and then convert it after the fact.
MainNoGUI: Remove a stub for an old host function
MainNoGUI: Declare an internal function as static

To stop gcc complaining about how it doesn't have a prototype.
DolphinWX: Allow building both GUI and NoGUI at the same time

Restructure our build system so we have multiple targets. Right now we
only build MainNoGUI if we are using X11, since that's the only truly
supported backend: the OS X code actually doesn't compile, according to
comments made on IRC.
CMakeLists: Try to fix the X11 detection on OS X