compat: add kernel range support to ckmake

compat: add kernel range support to ckmake

If we want to redistribute kernel compilation accross
a set of build machines ckmake needs to understand which
target kernels we want to work on. This enables kernel
ranges to be passed on to ckmake.

Here's one example, if you use -d it enables debugging
to print the kernel version computation:

mcgrof@tux ~/compat (git::master)$ ckmake -d 2.6.38..3.1
Going to use kernel ranges: 2.6.38..3.1
2.6.38 132646 <= 3.1.10 196864 <= 3.1 196864
2.6.38 132646 <= 3.0.18 196608 <= 3.1 196864
2.6.38 132646 <= 2.6.39 132647 <= 3.1 196864
2.6.38 132646 <= 2.6.38 132646 <= 3.1 196864
Trying kernel  3.1.10-030110-generic [OK]
Trying kernel  3.0.18-030018-generic [OK]
Trying kernel  2.6.39-02063904-generic [OK]
Trying kernel  2.6.38-02063808-generic [OK]

This should enable us to do compilation on a set of kernels
across a distributed set of machines now.

Signed-off-by: Luis R. Rodriguez <mcgrof@frijolero.org>