libsframe: add library versioning

libsframe: add library versioning

lisbframe was first released with Bintuils 2.40.  As the library
evolves, some changes will break the ABI.  Add library versioning for
users to manage these changes.

For the next release of the library (libsframe.so.1), incompatible ABI
changes are planned. These will include:
 - Deprecation of some APIs, like sframe_get_funcdesc_with_addr (), and
 - Change in the contract of some APIs (e.g., return type, behavior).

In libtool-version, set the current to 1 to prepare for the upcoming
release.  Reset revision and age to 0.

Add libtool-version file to EXTRA_DIST.

libsframe/
	* Makefile.am: Use libtool versioning.
	* Makefile.in: Regenerated.
	* libtool-version: New file.