Fix SSL cert validation against built-in root CAs

Previously, the TrustManagerFactory was initialized with an empty
KeyStore, which caused it to reject all certificates.  Initializing
it with a null KeyStore instead will cause it to use the default
root CAs built in to Android, which will allow certificates issued
by those root CAs to be used without nagging the user.
Added Tablet layout for 720dp and 960dp width
Add formatting for INVITE messages
bumped version
Fixed #203
Merge pull request #206 from justjanne/pr/fix-203

Fixed #203
Merge pull request #202 from justjanne/pr/tablet-ui

Added Tablet layout for 720dp and 960dp width
Merge pull request #197 from mamarley/formatinvite

Add formatting for INVITE messages
Fixed #207
properly initialized BufferList
Merge pull request #208 from justjanne/pr/fix-207

Fixed #207
Fixed #209
- Doesn’t switch to a buffer if the buffer doesn’t exist
Merge pull request #210 from justjanne/pr/fix-209

Fixed #209
bumped version
Fixed a bug where, upon adding a new network to the core, the app would become unusable
On adding a new network the app now adds the network directly without showing the "receiving networks" screen again
Fixed a bug where the connection status wasn’t shown at first connect
Fixed this bug again, this time properly
Fixed #204
Merge pull request #212 from justjanne/pr/fix-ui

Fixed several UI bugs
Merge pull request #211 from justjanne/pr/fix-new-network

Adding a network does not make the app unusable anymore
Merge pull request #194 from mamarley/sslcertvalidationfix

Fix SSL cert validation against built-in root CAs