Release 2.0.

Changes since v1.0

* Fix the number of CPUs used in compilation.
* Update package versions included in the 2.0 release.
* Make shared libraries relocatable.
* Fix build command for srfit-sasview.
* Reorder update steps according to build steps.
* Add option --clean for the install script.
* Prune git repositories before packaging.
* Use tarball package srfit-sasview 3.1.2.

Release 1.0

release candidate 1.0 alpha 1

Release 1.0 alpha 0.