Update documentation on SDK requirements
Merge branch 'develop' of https://github.com/akvo/akvo-flow into release/1.5.0
Merge branch 'release/1.5.0'
Issue #252 - Include Piwik tracking code
add war/index.html to .gitignore
Make instance configuration depend only on survey.properties.
R.arrays.servers now contains only server choices for debugging
Add summary of changes for released versions
Sanitize zipfile data in answer, deviceId, displayName and email columns
more fully, to prevent broken uploads.
Clean up and optimize buffer append code.
Prevent control characters, such as Tab, in device IDs.
Issue #256 - Enable REST security based on RestAuthFilter
Issue #255, prevent control chars in user names and email addresses
Merge branch 'develop' of https://stellanl@github.com/akvo/akvo-flow.git into develop
Issue #256 - Pass the uploadUrl as parameter

* Pass the `uploadUrl` as option for identifying the instance
* Remove the `?` from the querystring
Issue #185 - action to fix faulty questionAnswerStore type fields in datastore
Issue #185 - rawDataSpreadsheetImporter uses same convention as device for answer type
Clean up last traces of the APK's arrays.xml instance dependency
Merge branch 'develop' of https://stellanl@github.com/akvo/akvo-flow.git into develop
Issue #258 - fix validation for min-max on number question
Issue #185 - more subtle implementation of questionAnswer filter
Issue #185 - add comment to surveyInstanceSummarizer