Fix a crash in the monitor.

This patch set fixes a crash in the monitor loop in case of receiving an STH
with just an increased timestamp (i.e. tree size does not change).

It also logs non-critical network problems while fetching STHs.
add a minimal setup.py file so people can use python-ct as a lib
Make the "result" local variable const.
Remove the GetResultString static method.

It is used only in one general place, and is mostly duplication of what's already at its call sites.
Log "result" in the case where it is unknown.
Make the "sanity" local variable const.
add to contributors as requested
also add to authors as requested
update setup.py as suggested in PR discussion
Merge pull request #42 from rep/python-setup-py

Add a minimal setup.py file so people can use python-ct as a library.
Use pkg-config for json-c.
Make variables set from shell commands simply expanded.

Closes #45.
Python utility for validating and printing a json-formatted log list.
Add C++ to the continuous build.
Add a clean target for Python.
Add DNS support, comprising...

WIP on DNS.

Start of test harness.

Return leaf hash.

Temporarily include Eran's https://codereview.appspot.com/66940043/.

Also verify an inclusion proof for a leaf's hash.

Test work in progress.

Add missing file, move unmoved file.

Allow binary SCTs and logs on protocols other than HTTPS.

Remaining issues after a rebase.

Fix a couple of stray "https:"s.

Log responses.

Correct path.

Show error content.

Identify the type of the cert in the file name.

Calculate the right audit path length.

Get rid of cruft.

Fix merge error.

Add ldns library to LOCAL_LIBS.

Missing space.

Log instead of stderr.

Missing black line.

Remove redundant forward declarations.

Fix incorrect indent.

Run the DNS tests as part of the test suite.

Closes #25.

Remove redundant .. include.
Add ct-dns-server to .gitignore.
Disable server/ct-dns-server-test.py for now.
The tests in "cpp" depend on "python".

This is because of the Python protocol buffer files.
Add new dependencies on ldns to Travis.