Fixed kextdevmode check

The previous version would not correctly detect the kextdevmode=1 in case there were other bootflags, like -v.
Now it uses the exit status of grep (using string match) to understand whether "kextdevmode=1" is present or not.
v.1.0.1 - Stability bug fixes

Stability and security improvements:
Fixed a boot arguments overwriting bug, that could lead to a system
failure specific cases
Fixed a kext-dev-mode bug that prevented the OS to disable its drivers
protection
Fixed the strings utility presence check, to run as well from if the
script is run from the command line
Added a disk reparation step at the start of the patching procedure,
lowering failure risks on disks with permission issues
Added a verification that sudo is still active before patching
Merge branch 'pr/12'