run examples and demos with xwalk-launcher

As /usr/bin/xwalk binary doesn't exist anymore, we can not launch
examples and demos from xwalk binary.

In addition, this patch removes tizen-extensions-crosswalk script file
which appears to be useless right now.

BUG=XWALK-2370
Bump version to 0.97
W3C Telephony API implementation.

Implements the latest W3C Telephony API specification found at http://telephony.sysapps.org/
Requires the oFono telephony middleware and the BlueZ Bluetooth middleware for working with paired phones.

BUG=XWALK-1419
Fix review comments