Implemented lambda-cc.
lambda-cc is a cc wrapper which can be used by any project to have lambda-pp run on the source
files before touching the compiler. lambda-cc will search the environment to find the correct
CC to call after preprocessing of the source file has took place. lambda-cc searches the
following directories for lambda-pp [./, lambdapp/, /bin, /usr/bin], and the following
directories for CC [/bin, /usr/bin]. lambda-cc considers [cc, gcc, clang, pathcc, tcc] as valid
CCs and will search for those. The environment variable LAMBDA_PP can also be used to specify
lambda-pp's path.
Allow lambda-cc to be used in the linking stage.
Merge branch 'lambda-cc'