[Chicken-hackers] new egg install update

[felix . winkelmann]

Hello!

I've pushed a few changes regarding the new egg install and would be
happy about feedback regarding these changes:

* chicken-status + chicken-uninstall use exact matching by default (use -match
  to use globbing)

* there are now 2 env vars:

    CHICKEN_REPOSITORY_PATH: one or more directories separated by ":" (";" on 
Windoze)
        that are searched by "require..."/"import", the first that contains a 
.so or .o is used.

    CHICKEN_INSTALL_REPOSITORY: where eggs are installed (only one directory, 
if set)

    chicken-uninstall only sees CHICKEN_INSTALL_REPOSITORY (or the default 
repo).
    chicken-status sees CHICKEN_INSTALL_REPOSITORY (or the default), unless 
"-all"
        is given.
    chicken-install normally uses CHICKEN_INSTALL_REPOSITORY, but checks
        CHICKEN_REPOSITORY_PATH when looking for already installed eggs.

    CHICKEN_REPOSITORY has been removed.

    In a cross-chicken, using -target always refers to the target repo, 
regardless
    of any vars.

    I haven't tested all of this too much, yet.

    Doing path-splitting is done by an internal prcoedure in eval.scm
    (##sys#split-path), used for include-path splitting as well, and this uses 
the
    platform specific split char (":" or ";").

    types.db + modules.db lookups use CHICKEN_REPOSITORY_PATH, if set,
    or overriding CHICKEN_INSTALL_REPOSITORY will break the compiler as
    types.db can not be found.

* -no-install-deps is back


felix