Replace free() with NULLFREE().

This changes were made as part of CLOCKFIX patch development.

Patch by: theparasol

git-svn-id: http://streamboard.de.vu/svn/oscam/trunk@9277 4b0bc96b-bc66-0410-9d44-ebda105a78c1
clockfix: Add basic clockfix infrastructure.

This just introduces the infrastructure and configuration
parts of CLOCKFIX patch. It doesn't change OSCam to actually
use CLOCK_MONOTONIC and doesn't switch time checks to milliseconds
instead of seconds.

This is just a preparation and shouldn't change OSCam's timing
behaviour.

WARNING: If you see build failure like this:

undefined reference to `pthread_condattr_setclock'

Report it in the forum and disable CLOCKFIX configuration.

`./config.sh -D CLOCKFIX`

Patch by: theparasol

git-svn-id: http://streamboard.de.vu/svn/oscam/trunk@9278 4b0bc96b-bc66-0410-9d44-ebda105a78c1
clockfix: Convert clock type to enum.

Clean up of CLOCKFIX related code a bit.

git-svn-id: http://streamboard.de.vu/svn/oscam/trunk@9279 4b0bc96b-bc66-0410-9d44-ebda105a78c1
clockfix: Old uclibc versions do not have pthread_condattr_setclock().

uclibc <= 0.9.28 is known to not have pthread_condattr_setclock().
This was found when trying to compile CLOCKFIX enabled OSCam using
AZBOX toolchain.

Please report any other build failures related to missing
pthread_condattr_setclock() in the forum.

git-svn-id: http://streamboard.de.vu/svn/oscam/trunk@9280 4b0bc96b-bc66-0410-9d44-ebda105a78c1