Separate conference timezone into separate value
Add support for open WiFi networks

You just have to have a null value for WIFI_PASSPHRASE in
Config.java, and the network will be set up as open.
Fixed actionbar icon bug

Now we have a proper conference ActionBar icon and we use it.
Fix for unreadable main text color in settings
Updated for ADD
Merge pull request #5 from rock3r/open_wifi

Implement support for open conference WiFi.
Merge pull request #8 from rock3r/actionbar_icon

Fix ActionBar icon implementation.
Merge pull request #10 from rock3r/settings_textcolour

Fix settings main text colour
Merge branch 'master' into ADD2014

Conflicts:
	android/src/main/java/com/conferenceengineer/android/iosched/Config.java
	android/src/main/res/drawable-xhdpi/conference_actionbar_icon.png