Moved some lines and deleted old code

* Removed Compiler ELF references from rpcs3.cpp
* Reordered the menu bar lines.
* Moved the construction of some panels of MainFrame from rpcs3.cpp to
MainFrame.cpp
PKG Loader rewritten

* Rewritten unpkg.c -> Loader/PKG.cpp
* MainFrame::InstallPkg now *only* installs the PKG.
* Fixed crash when unpacking big debug PKG files.
* Debug PKGs are no longer recrypted.
* 'About...' dialog updated to remove PKG-related notice.
* Unpkg removed.

NOTE: The class PKGLoader is using wxWidgets functions to access the
files. I think VFS would be better, but the Emulator isn't necessarily
running when installing the PKG. In the other hand, initializing VFS
with RPCS3 may be somewhat risky... Any alternatives?

TODO: Get rid of the decrypted "*.dec" files, and try to decrypt and
read contents of the PKG on the fly using the information stored in
m_entries.
Minor changes in RSXTexture.h and PKG Loader

* Moved RSXTexture from RSXThread.h to RSXTexture.h
* Renamed RSXTexture::Getmipmap to RSXTexture::GetMipmap
* Used more GCM texture format constants in GLGSRender.h
* PKG Loader: Added an "Overwrite?" dialog in case the folder
dest+titleID (i.e. "/dev_hdd0/game/"+titleID) already exists. Note that
in that case, the game won't be installed regardless of the option you
choose on the dialog.
Merge pull request #46 from krofna
Merge refactoring branch & Krofna's pull req. #46