Added more information to kernel compilation part.

* Introduced way to verify toolchain setup.
* Used pre-set variable where possible.
* Straightened out information on deploying & verifying new kernel.
Fixed processor count in zramswap script.

zramswap uses grep to count occurences of 'processor' in /proc/cpuinfo,
but it reports wrong count (2 instead of 1) due to processor being
labeled as 'ARMv6 processor'. Added a start-of-line anchor to solve that
problem.
Updated zramswap link

The link now points to Mobica's public repository.