gradle: Allow absolute paths to keystore files
gradle: Allow storeType to be set (allows using .p12 files)
CB-7726 fix typo in gitignore: ant-built -> ant-build

github: close #131
CB-7758: Allow content-url-hosted pages to access the bridge

This allows e.g. jsHybugger to create pages with access to Cordova APIs.
We restrict access to content provider URLs which are at subdomains of the application itself, ie, begin with "content://com.your.package.id."