libsmack: fix parsing of CIPSO settings

Adjust CIPSO parsing to expected kernel format:
- maximum number of categories is 184
- each category value must be between 1 and 184

Change-Id: Ic5e4ccd2104ed3284a873087339bf792536b2125
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
libsmack: use bit array to reduce the size of struct cipso_mapping

To decrease size of struct cipso_mapping, categories are now stored in a
bit array. This reduces the size of the whole struct.
On a i386 machine it will occupy 292 bytes instead of 1004.

Change-Id: I5e9119ee822131cd0adcb479359a0693f094aee6
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Merge pull request #116 from rafal-krypa/issue116

libsmack: fix parsing of CIPSO settings