Variable and hook functions

Functions for working with variables:

var_append PATH ":" "$HOME/bin"
var_insert CC_WRAPPER_INSERT " " "-O3"
var_remove CC_WRAPPER_INSERT " " "-O3"
var_remove_regex CC_WRAPPER_INSERT " " "-O.*"
var_insert_before_regex patchfiles " " "mypatch.diff" ".*\/foo.diff"
dump_env

Functions for working with hooks:

hook_add preconf 2 ". $confdir/postsysfiles.in"
hook_eval preconf
hook_dump