Add support for RHEL kernel forks (RHEL, CentOS, Oracle Linux) and changed INSTALL.sh

[rmnscnce]

RHEL kernel forks are known to have modified (usually backported) components such as struct names. This branch adds additional files that brings support for them. Currently it's only binder.c that have the build discrepancy with mainline kernels, but I have added also the rest of the module sources to ease the "porting" if there will be any more modifications to the RHEL kernels that affect the module build process.

I also changed the INSTALL.sh so it will run completely as root (not just calling sudo line-by-line). I also added an installation confirmation prompt there to make sure the installation is purely intentional. Of course, I added detection logic for RHEL kernels