halcc: Introduce halcc library

halcc: Introduce halcc library

The halcc stands for hal compatibility checker.

Tizen hal-apis can specify what feature and version it expects to
hal-backends in manifest file. The halcc library deserializes and
utilizes the information for checking compatibility between
hal-api and hal-backend.

For example, a hal-api specifies what it needs in xml file:

  | <!--hal-api-xxx.xml-->
  |
  | <manifest version="1.0" type="platform" level="2">
  |     <hal>
  |         <name>AAA</name>
  |         <version>3.1</version>
  |         <transport>passthrough</transport>
  |     </hal>
  |     ...
  | </manifest>

It means that the hal-api expects and requires hal-backend module name
of AAA, and version of 3.x where x >= 1.
(See semantic versioning, https://semver.org)

These are collected and tested by the halcc library.

Currently only the function below is provieded
 - int halcc_check_compatibility(const char *hal_api_manifest_dir,
     halcc_compatibility_cb callback, void *user_data)
   : It collects manifest files at hal_api_manifest_dir and checks
     whether the hal-backends have compatible what hal-apis have
     specified. For each specified <hal> in manifests, callback is
     invoked.

Change-Id: Ibb16c378f6fbe08750b6df7db99ee6626bcfd033
Signed-off-by: Youngjae Cho <y0.cho@samsung.com>