First cut an enhancing BlueKai android sdk.

- fixed bugs around updating site id and devMode settings.
- updated targetSdkVersion to 19.
- Not sending identifierForVendor anymore in the POST call.
- better debug logging in bluekai sdk logger. Now it will print log line as "class.method():line number"
- getter and setters for all the public properties in main Bluekai class.
- added useHttps flag, its getter and setters and also updated bluekai sample app to use this setting.
Fixes around devMode and useHttps.

- make devMode and useHttps work together.
- in devMode make call to bluekai sandbox url.
- Fix the issue where in devMode, the pop up was not showing up.
changes around opt-in/opt-out. Custom BGColor support.

- while changing optout setting, no communication with server anymore.
- Initialize method for settings layout tab now accepts background color as well.
- added new method with name “setOptInPreference” and deprecated the old method “setOptIn”
- added new method “getOptInPreference” to get optIn value.
New putAll method and removed commented out code.

- added putAll(Map) method and deprecated put(Map) method in favor of putAll(Map)
- removed commented out code.
- Removed TC from Bluekai.java file.
Fix Logger settings and add comments to getInstance method.
Merge branch 'SDKEnhancements' of https://github.com/BlueKai/bluekai-android-sdk into SDKEnhancements

Conflicts:
	sdk/src/com/bluekai/sdk/BlueKai.java
Updated README.md
Couple of fixes and changes:
- Code review comments.
- Made Logger changes to work with debug, info, error and warn.
- changed useHttps to httpsEnabled in Bluekai.java and DevSettings.java.
- Updated CHANGELOG
- Updated README
Fixing indentation.
Fixing indentation.
Merge pull request #3 from BlueKai/SDKEnhancements

Sdk enhancements