[Information] Make a common class for integrating key-value functions

[Information] Make a common class for integrating key-value functions

- You can get the runtime feature with using string key
  - http://tizen.org/runtimefeature/FEATURE_NAME
- Information class just checks whether this key is
  runtime feature or not and pass to the appropriate class
- For convenience, key and type check functions are
  embedded in the get function
  - Before run get function, these are automatically run

Change-Id: I0f1f6137afbb1f0409d16b433376b2d3de46b2c5
Signed-off-by: Kichan Kwon <k_c.kwon@samsung.com>