Upgrade to coverage 3.7.1 and have it auto-build itself on first use.

third_party/coverage-3.7.1/doc/install.rst

Index: third_party/coverage-3.7.1/doc/install.rst
diff --git a/third_party/coverage-3.6/doc/install.rst b/third_party/coverage-3.7.1/doc/install.rst
similarity index 77%
rename from third_party/coverage-3.6/doc/install.rst
rename to third_party/coverage-3.7.1/doc/install.rst
index 9539093b4f2706aacdbaff1a0253705de04502bb..bc8097a21ad84a9801c39480b6a8400f6cd27322 100644
--- a/third_party/coverage-3.6/doc/install.rst
+++ b/third_party/coverage-3.7.1/doc/install.rst
@@ -18,6 +18,8 @@ Installation
 :history: 20121223T180800, updated for 3.6b2.
 :history: 20121229T112400, updated for 3.6b3.
 :history: 20130105T174400, updated for 3.6.
+:history: 20131005T210600, updated for 3.7.
+:history: 20131212T213500, updated for 3.7.1.
 
 
 .. highlight:: console
@@ -48,8 +50,9 @@ or even::
 Installing from source
 ----------------------
 
-Coverage.py includes a C extension for speed. If you are installing from source,
-you may need to install the python-dev support files, for example with::
+Coverage.py includes a C extension for speed. If you are installing from
+source, you may need to install the python-dev support files, for example
+with::
 
     $ sudo apt-get install python-dev
 
@@ -58,9 +61,9 @@ Installing on Windows
 ---------------------
 
 For Windows, kits are provided on the `PyPI page`__ for different versions of
-Python and different CPU architectures. These kits require that `setuptools`_ be
-installed as a pre-requisite, but otherwise are self-contained.  They have the
-C extension pre-compiled so there's no need to worry about compilers.
+Python and different CPU architectures. These kits require that `setuptools`_
+be installed as a pre-requisite, but otherwise are self-contained.  They have
+the C extension pre-compiled so there's no need to worry about compilers.
 
 .. __: coverage_pypi_
 
@@ -68,13 +71,13 @@ C extension pre-compiled so there's no need to worry about compilers.
 Checking the installation
 -------------------------
 
-If all went well, you should be able to open a command prompt, and see
-coverage installed properly::
+If all went well, you should be able to open a command prompt, and see coverage
+installed properly::
 
     $ coverage --version
-    Coverage.py, version 3.6.  http://nedbatchelder.com/code/coverage
+    Coverage.py, version 3.7.1.  http://nedbatchelder.com/code/coverage
 
 You can also invoke coverage as a module::
 
     $ python -m coverage --version
-    Coverage.py, version 3.6.  http://nedbatchelder.com/code/coverage
+    Coverage.py, version 3.7.1.  http://nedbatchelder.com/code/coverage