gitignore: swp, swo

ignore vim swap files
emgui: case sensitivity fixes

Make it compile on linux where filenames are case sensitive
emgui: opengl header path for linux
ogl_editor: no gl header includes in linux

gl headers in TrackView.c seem to be unnecessary
ogl_editor: letter case fixes

Make it compile on linux where filenames are case sensitive
ogl_editor: make it compile in linux

just a quick test with a manual compilation script
ogl_editor: link with GL and m in linux

it compiles and links!
ogl_editor: initial SDL window code

graphics visible!
ogl_editor: build for linux with tundra

Remove testing scripts and use the build system in linux too
ogl_editor: linux/SDL code for everything

Finish the linux code, should be mostly coherent with win and mac.
Update the readme file too.

Just SDL basics for creating the window with opengl context, and passing
the mouse and keyboard inputs along. Menus are not displayed, but the
hotkeys are the same as in Windows. File dialogs use terminal input and
color dialog isn't implemented.

This is quite straightforward and platform-independent, so should be
pretty portable too.
ogl_editor: select first track initially

When getting the tracks from the demo, select the first one when it
comes, otherwise we end up focused in the editor but nothing selected.
ogl_editor: set bookmarks NULL when freeing them

trackData's bookmarks are realloc()'d later when bookmarks are added if
the pointer is not null, and realloc gets upset if it's freed already.