Implemented disk_partitions_phys
Added swap_memory, cpu_times, cpu_perent, cpu_times_percent and some enums

Fixes #1 from Andre Ryser. Ths is not directly merged since I
edited it to remove some whitespace modifications.
Deletes trailing whitespaces.

Signed-off-by: Noufal Ibrahim <noufal@nibrahim.net.in>
Merge remote-tracking branch 'remotes/origin/pr/5'

Conflicts:
	driver.c
	pslib.h
Adds contribution guidelines.
resolved merge conflict