Add Travis CI configuration file for automatic build tests

Github provides a Travis CI integration which makes it easy to have a quick
check of a patch before a pull request is accepted. It is not enough to prove
the correctness of a contribution but at least helps to avoid some of the worst
build problems.

This feature *must* be enabled by the mupen64plus administrator *before this
commit is merged*:

- https://travis-ci.org/profile/mupen64plus
- Login via your Github account
- Make sure you are on "https://travis-ci.org/profile/mupen64plus"
- Switch repository to "On"
Provide SDL_SCANCODE_?GUI <-> SDLK_?SUPER mapping
Fix list_for_each_entry* define conflict with lll
Don't assign pointer to integer qstackindex
Merge pull request #32 from fayvel/travisci

Add Travis CI configuration file for automatic build tests
Merge pull request #33 from fayvel/sdl_key

Provide SDL_SCANCODE_?GUI <-> SDLK_?SUPER mapping
Merge pull request #34 from fayvel/list

Fix list_for_each_entry* define conflict with lll
Merge pull request #35 from fayvel/warnings

Don't assign pointer to integer qstackindex
Move no_compiled_jump to recomp module.
Prefer enum over macro for CP0 registers.

Previous macros had high risk of colliding with other identifiers because they were not
capitalized, nor prefixed. Furthermore, some identifier were relatively common (Context, Count,
Compare, ...).
Additionally, cp0 registers array has been explicitely marked as global (g_ prefix).
Merge pull request #36 from bsmiles32/cp0_regs

CP0 regs + no_compiled_jump
Merge pull request #28 from ricrpi/master

Better sl function for arm
speed test code
Add missing bracket in isset_bitmask makro
Merge pull request #37 from fayvel/master

Add missing bracket in isset_bitmask makro
Refactor interrupt queue.
Remove non-existent function prototypes.
Remove commented code.
Implement add_interupt_event in term of add_interupt_event_count.
init special directly.