produces a list of maildirs found under the argument dir

* LICENSE
* .hgignore
* Makefile
* maildirs.cpp
confirmed to work with "g++ (GCC) 4.2.1 20070719  [FreeBSD]"

this will only last until I feel inclined to use a c++0x feature
such as "auto".  on the other hand, that could mean "forever"
since to requirements are tiny and the code trivial as is.

used `make _CXXRT=/usr/lib GCCVER=` to build with above-mentioned
compiler on FreeBSD-8.0

* Makefile

  allow setting _CXXRT on the command line
drop gratuitous dependency on Boost.Format

I had bigger plans with the usage string, but the interface
came out simpler.

* maildirs.cpp

  boost::format -> std::string::operator+
std::make_pair comes from <utility>

* maildirs.cpp
is_maildir(p) first checks is_directory(p)

only then test if is_directory(p / "cur") etc

also get rid of an unnecessary "continue"

* maildirs.cpp
don't segfault if argc == 0

* maildirs.cpp
bad usage yields exit 2, non-dir argument gets 1

* maildirs.cpp
execution with no arguments yields usage string

it's an easy way to see what is expected

* maildirs.cpp
non-directory first argument yields usage string as well

because simply exiting with 1 is weak

plus, error checks concentrated at the beginning of main()
also, using std::cerr etc. didn't paid for themselves, gone

* maildirs.cpp
#define BOOST_FOREACH foreach, it's needlessly long

* maildirs.cpp
LICENSE should include the (C) line

* LICENSE
Makefile tweaks

- C++ runtime handling changed, default expected in /usr/lib
- stray $(LIBS) leaves $(LDFLAGS)

* Makefile
more Makefile tweaks

- should build on machines without gfilt
- be explicit about C++ dialect used

* Makefile
(experimental) build description for Boost.Build v2

* Jamroot
* .hgignore
fix for a libboost_system-related link error

maybe a change since whenever i last built this?

g++ -pedantic -std=c++98 -O3 -Wall -Wextra -Werror -Wfatal-errors -I/usr/include  -Wl,-s -Wl,-L /usr/lib -Wl,-rpath /usr/lib -Wl,-L /usr/lib  maildirs.cpp  -lboost_filesystem -o maildirs
/usr/lib/gcc/i586-suse-linux/4.7/../../../../i586-suse-linux/bin/ld: /tmp/ccaJi5rg.o: undefined reference to symbol '_ZN5boost6system15system_categoryEv'
/usr/lib/gcc/i586-suse-linux/4.7/../../../../i586-suse-linux/bin/ld: note: '_ZN5boost6system15system_categoryEv' is defined in DSO /usr/lib/libboost_system.so.1.49.0 so try adding it to the linker command line
/usr/lib/libboost_system.so.1.49.0: could not read symbols: Invalid operation
collect2: error: ld returned 1 exit status
make: *** [maildirs] Error 1
.gitignore based on .hgignore
README.rest to placate github

seriously, READMEs are good, thanks for the reminder.
README.rest: clarify accepted arguments
nomenclature change to match README.rest

{dir,top} -> root, sep -> {terminator,term}
maildirs.1: initial stab at manpage