Merge pull request #36 from clifffrey/master

A few small contributions from meraki
String: Add (unsigned char *, int) constructor for convenience.
Add a CryptoTest element that tests MD5.
MD5 fix: Allow md5_init to fail.
CryptoTest: Make it work in the kernel.
Changes to compile cleanly with LLVM clang.
Remove obsolete -fvtable-thunks detection.
Prepare to release 2.0.1.
MD5 functions: Add md5_reinit, which will be faster than md5_init in kernel

because it need not reload the MD5 crypto function.

Signed-off-by: Eddie Kohler <ekohler@gmail.com>
Mark undistributed files.
Avoid warnings when compiling C code in the kernel.

Changes to CFLAGS in 02bc417e32a4b1598b6a587c3724c1e7ada8efbb induced the
warnings.

Signed-off-by: Eddie Kohler <ekohler@gmail.com>
Update configure.
shell_command_to_output_string: Hand-roll popen.

Because it appears that this late Ubuntu's glibc, at least, doesn't leave
tmpfile() file descriptors open across popen().  Yuck!

Signed-off-by: Eddie Kohler <ekohler@gmail.com>
Clicky: The "Run" button runs the current configuration buffer.

Signed-off-by: Eddie Kohler <ekohler@gmail.com>
Minor authors updates
Remove click_dmalloc_totalmem (it is not useful).
add warning on pulling ICMPPingSource with interval parameter set
replace tab character by correct amount of spaces
Fix incorrect assertion on packet pool for --enable-user-multithread.

The code was correct, the assertion wasn't!  Roman Chertov report.
Improve a configure message.