Use KitKat (19) as target sdk since robolectric 3.1.2/sqlite4java
does not understand "WITHOUT ROWID" tables.
Also, add constants for user's gender and document some things.
This avoids a lot of problems because java
- does not know unsigned values
- jvm and dalvic do not internally support byte and short
- sqlite does not know them either
Created a new device-independent class ActivityUser to hold the data
Moved the constants from the miband constant class to the ActivityUser class
Removed the miband-specific in favor of common-prefixed preferences (with upgrade support for legacy values)
Changed the way the gender is stored to an integer value
Removed the hardcoded default values for user data in favor of static fields of the ActivityUser class
