coregl: Re-organize log solution

coregl: Re-organize log solution

1. Create macro DLOG_DEFAULT_ENABLE to determine whether to use dlog or not
2. Replace orginal LOG functions with new created API COREGL_ERR, COREGL_WARN and COREGL_DBG
   - default log output: dlog
   - default log level: debug
      debug: COREGL_LOG_LEVEL=1, warning: COREGL_LOG_LEVEL=2, error: COREGL_LOG_LEVEL=3
   - howto change default log level or output?
     1) build time: change spec file's COREGL_DEFAULT_LOG_LEVEL / COREGL_DLOG_ENABLE macro
     2) execute time: execute with COREGL_LOG_LEVEL / COREGL_TRACE_DLOG   option
       example command: COREGL_LOG_LEVEL=2 COREGL_TRACE_DLOG=0 COREGL_TRACE_API=1 elementary_test -to "GLView gears"

3. Remove orginal color schemes and symbol "\n" since new API specify uniformly

4. Replace COREGL_LOG with TRACE for trace path
   - example command for logging to file: COREGL_LOG_FILE=/tmp/coregl_log.txt COREGL_TRACE_API=1 elementary_test -to "GLView gears"

Change-Id: I61cbc8d6dad6ce86ba4391c6dc846d08188ffaeb
Signed-off-by: Zhaowei Yuan <zhaowei.yuan@samsung.com>