Mbox: Add support for reading from filehandle
Mbox: Add support for unescaping From lines
Mbox: Add function next_messageref() which returns ref to string
Mbox: Add function next_from() which returns the From_ line for next message
Mbox: Fix parsing mboxcl & mboxcl2 archives which have lot of spaces in Content-Length or Lines headers
Mbox: Add support for non-seekable filehandles
localize $/ as needed before reading from mbox fh
run tests in predictable order, for sanity's sake
changelog for Pali Rohár's changes
Moerge branch 'mbox-changes'
blank lines for $VERSION assignment
v0.859

        - all the changes in this release contributed by Pali Rohár
        - support for mboxcl and mboxcl2
        - add ability to read from a filehandle
        - add next_from and next_messageref methods