Added Konstanz on-boat WiFi to blocklist
Merge pull request #935 from garvankeeley/nullptr-log-msg

Null pointer in logging http error, fixed.
Empty content body not handled after successful post.
https://github.com/mozilla/MozStumbler/issues/930
Added setDoOutput to the POST method because android is stupid.
Created a proper developer settings screen. Previously the KML Activity
was being used for this. Currently it only has the KML stuff.
Change main app to be the upload listener.
As part of the quickie hookup for metrics upload, the metrics was the
upload listener, and because of the transient state of the metrics, it
also had a timer to check if uploading.
MLS location layer requires additional memory and network.
Make this layer toggle an option that defaults to false.
Update README.md
Merge pull request #942 from ashleyblackmore/patch-1

Update README.md
Merge pull request #927 from JensErat/Konstanz-katamaran

Added Konstanz on-boat WiFi to blocklist
Merge pull request #937 from garvankeeley/bug-network

Empty content body not handled after successful post.
Merge pull request #939 from garvankeeley/developer-screen

Created a developer settings screen.
Merge pull request #940 from garvankeeley/mainapp-upload-listener

Cleanup Metrics upload monitoring: Change main app to be the upload listener.
Merge pull request #941 from garvankeeley/option-to-enable-mls-option

MLS location layer requires additional memory and network.
Metrics View UI changes: map legend
- removed this session cell and wifi count
- removed toggle for showing observation type
- added Map Legend section
bumped version to 0.40
* serialized the stack trace on error when using Log.e()
* added a Log.d level logger that does not emit output to the GuiLog.  Only info, warn and error will write to the gui log.
Changed Prefs::createGlobalInstance and ClientPrefs::createGlobalInstance to return the instance
write the mozilla api key into the prefs on MainApp creation.
Changed HTTPResponse to only write a Log.debug level message so that it does *not* go to the GUI log.