destiny: fixed condition for error handling
send_tcp returns either the length of the sent data,
or -1, if an error was detected.

The current implementation checks for != 1.
This results in executing the error case, although
there was semantically no error returned from send_tcp.
core/include/arch/irq_arch.h: fix typo and trailing whitespaces
Merge pull request #1308 from N8Fear/fix-typo-and-whitespaces

core/include/arch/irq_arch.h: fix typo and trailing whitespaces
cpu: renamed cortexm_common->cortex-m3_common and cleanup
pnet: silence unused argument warnings
Merge pull request #1295 from haukepetersen/mv_cpu_cortexm-common

cpu: renamed cortexm_common->cortex-m3_common and cleanup
Merge pull request #1312 from mehlis/pnet-unused-param

pnet: silence unused argument warnings
cpu:cortex_common: add core_panic function
Merge pull request #1313 from thomaseichinger/cortexm_crash

cpu:cortex_common: add core_panic function
Merge pull request #1280 from cgundogan/fix_send_tcp_error_check

destiny: fixed condition for error handling of send_tcp in destiny_socket_send
make: remove local definitions of (ELF|HEX)FILE

We have sane defaults for `ELFFILE` and `HEXFILE` in the root
`Makefile.include`. The local definition for `ELFFILE` of mbed_lpc1768's
`Makefile.include` was wrong, which caused e.g. `make buildsize` to
fail.