move rust-crypto to deps/
md5sum: remove Makefile
uutils: add md5sum
Merge pull request #286 from ebfe/uutils

uutils: add md5sum
Fix build dependencies in the Makefile
Change md5sum/rust-crypto to deps/rust-crypto
Prevent rebuilding of up-to-date utilities
echo: check argument length when parsing options
fmt: correct tab support, better formatting

In brief:

- Lines no longer end with trailing whitespace.
- fixed length calculation when tabs are present
- word splitting gives more info to the line
  breaking process, which should be useful for K-P
- code cleanup here and there
- K-P is not implemented yet. That's next. There
  is some dead code in linebreak.rs that forms the
  basis for K-P.
- Performance has regressed somewhat; we're now about
  60% slower than GNU fmt (formerly about 20%), but we
  are basically on par with OpenBSD fmt.
- addressed comments from Arcterus on PR

This is a squash of the following local commits:

 1feceb0 - address comments from Arcterus on PR
 b36aa90 - use word_nchars rather than w.len() for first word
 f44a629 - proper tab handling
 4f57593 - added tab analysis info to WordInfo
 211f4a5 - pass WordInfo by ref
 80e14b9 - overhaul word splitting apparatus
 d29f2e6 - tidy up the breaking by passing arg struct pointer
 d8020df - lines blank save for prefix act as par separators
 8bd7f1e - fixed tab behavior in -u
 a2387f7 - cleaner prefix handling ; cleanup ; prep for K-P
Merge pull request #290 from kwantam/master

fmt: correct tab support, better formatting
seq: now passes about half of the Busybox tests
seq: handle --
Merge pull request #289 from Arcterus/gitmodules-update

Assorted fixes and improvements
cat: fix build
add multicall build to travis
Merge pull request #291 from ebfe/cat

cat: fix build
Merge pull request #292 from ebfe/travis

add multicall build to travis