Added helper script for checking git status.

Added script, which checks if there is unstaged/uncommitted/untracked content in working tree. Returns 0 if none found, otherwise returns 1.
Do not print exit value.
Initial version of version number generator.
Fixed exit code parsing.
Check git status when building
Run build hooks when running lb build, instead of Makefile.
Updated version helper, allow hiding git commit hash.
Allow building dev/dist images.
Updated version helper, initial stub for timestamping.
Use scripts/version.helper as source for version number.
Simplified Makefile.
Use version.helper for version number.
Create build.log in Makefile.
Updated version number structure.
Do not create checksums.
Shorter target directory.