ipc: add basic support for L4_Sleep
add preliminary Travis CI support
travis-ci: properly install GNU Tools for ARM Embedded Processors
travis-ci: defer to defconfig

In the future, F9 is expected to support more devices, and it should
be straightforward to enable the build matrix of travis-ci by specifying
the board name.
Merge pull request #77 from ahmedammar/master

ipc: add basic support for L4_Sleep
mpu: move to platform as not all plaforms use ARM's mpu

- Kinetis MCU from FSL uses a different MPU than ARMs

Fix#78
Merge pull request #79 from ahmedammar/master

mpu: move to platform as not all plaforms use ARM's mpu
linker: move scripts to $(CHIP) sub-folder

Fixes #80
Merge pull request #81 from ahmedammar/master

linker: move scripts to $(CHIP) sub-folder
add Ahmed Ammar into author list
ipc: do_ipc should not access thread context's stack pointer if not initialized.

Fixes f9micro/f9-kernel#82
Merge pull request #83 from ahmedammar/master

ipc: do_ipc should not access thread context's stack pointer if not initialized.
Thread Removal: Fix thread could not be removed.

Fixes #74

sys_thread_control: Now, utcb is used only for thread creation.  Move its
checking for thread creation.

thread_destroy: Because "parent" is usually equal to "caller", we should remove
"thr" first and then move its children to "caller".  Otherwise, "parent->t_child"
may be assigned to "thr->t_child". Then, it is incorrect to remove "thr" from
"parent->t_child".