Fix typo

Fix missing quote in README.md

Fix missing quote in `sed` example.

This is purely a bugfix bump that works on GHC 7.6.3,
as currently found in Debian stable and Ubuntu LTS.

This release is dedicated to Tom Lehrer, who lives
the dream of having quit just to loaf about indefinitely.

Add a warning when you mkdir with both -p and -m.

When using -p, parent directories will not be created with the mode
specified with -m and will instead be created using the default behavior
controlled by umask.

Add more variables which are assumed to be set.

This commit adds LC_MONETARY, LOGNAME, LD_LIBRARY_PATH, LANGUAGE,
DISPLAY, HOSTNAME, KRB5CCNAME, XAUTHORITY to be ignored when used
without initialization.

Add --color switch