I started replacing functions from can_drv.c
so we can get rid of the last dependencies.
After the last commmit a lot of errors was
introduced at compile time. This commit
tries to fix that.
As for now the code can compile but will likely
not run correctly as the baud rate is never set.
With this commit the libat90 library is no
longer dependent on Atmels can_std library.

This commit introduces our own can_init
function that sets a fixed defined baudrate.

Also minor changes in can macros has been made,
which means the user is now more responsible
for setting up the canbus functionality
with the right interrupts enabled.
This is important for keeping basic
execution flow control at node level and
not at library level.

Nodes affected by all these changes have
been updated with the new interface and
have passed testing.
Deleted unused Atmels library files in libat90/can_std.
Merge branch 'master' of https://github.com/UnicornRaceEngineering/g5-nodes