libmisc/shell: Edit history hack is corrupting memory. Remove it.

The hack was a debug aid and is not needed.

Close #2203.
m68k/mcf5235: GCC 4.9.2 generates invalid code for Init5235.

Move the vector table copy out of the Init5235 source to avoid
stipping the GCC bug.

Fixes #2204.
libtests/complex,math: Prevent optimizations

For constant arguments GCC calculates the values of the math library
functions at compile-time.

close #1741
Fix context switch code, account for red-zone and use callee saved resgister for restoring stack pointer after returning from interrupt user C handler
Fix bug: save status instead of config register
increase tick timer time
Merge remote-tracking branch 'upstream/master'