android-sdk: update wrapper scripts.

- Clean up some of the user facing copy.
- Add examples of how to install the various tools required to use the sdk.
- Change the interpreter of wrapper scripts to /bin/bash
- Clean up the wrapper scripts.
- Change the default version of the Android Build Tools to 19.0.3.

Closes #27587.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
tinyxml2 2.0.2: new formula

tinyxml2 is a light-weight c++ library for parsing xml. It
was previously submitted as a head-only formula in #23381
but was put on hold until releases could be tagged upstream.
The 2.0.2 release has just been tagged.
tinyxml2: add test that uses pkg-config to search for library
tinyxml2: add basic test for compiling and linking
Update tinyxml2.rb

Remove pkg-config test.
tinyxml2: add 2.0.2 bottle.