Readme.markdown : add build status links

Displays the status of the master and develop branch
from jenkins right in the Readme as it is rendered
on the main page of the repository on github.
Android build.xml : add post build step to build doc

Hooks into the build.xml in api-docs directory to
build the doxygen documentation for the version of
Readium SDK that was just built.
Merge branch 'build-android-doc-after-sdk' into develop
Merge pull request #63 from datalogics-bhaugen/add-build-status-to-readme

Add build status to readme
README.markdown : add jenkins build status for windows

Adds the status of the different windows configurations
that jenkins is now aware of, all are currently
failing.
Merge branch 'add-windows-build-status-to-readme' into develop