Catch apparently supports targeting C++03, so use an inline function
instead.

Catch passes ::tolower into std::transform with string iterators.
::tolower has the signature int(int), which triggers a stealth narrowing
warning inside std::transform, because transform calls
*_Dest = _Fn(*_First), which implicitly narrows an int to a char.

For this particular application the narrowing is fine, so explicitly
narrow in a lambda.

Catch passes an RNG which accepts int to random_shuffle. Inside
random_shuffle, the STL tries to call that RNG with the difference_type
of the user provided iterators. For std::vector, this is ptrdiff_t,
which on amd64 builds is wider than int. This triggers a narrowing
warning because the 64 bit difference is being truncated to 32 bits.

Note that this RNG implementation still does not produce a correctly
uniformly shuffled result -- it's currently asserting that std::rand
can produce 1000000 which is false -- but I don't know enough about
how much repeatable shuffles are necessary here, so I'm leaving that
alone for now.

- completes #717

This is the first part to resolving #717

Closes #679

This commit fixes the following scenario:
  * You have a test that compares strings with embedded control
  characters.
  * The test fails.
  * You are using JUnit tests within TeamCity.

Before this commit, the JUnit report watcher fails on parsing the XML
for two reasons: the control characters are missing a semicolon at the
end, and the XML document doesn't specify that it is XML 1.1.

XML 1.0 --- what we get if we don't specify an XML version --- doesn't support embedding control characters --- see
http://stackoverflow.com/questions/404107/why-are-control-characters-illegal-in-xml
for all of the gory details.

This is based on PR #588 by @mrpi