Changes between hp48cc 1.2 - hp48cc 1.3

* Added more examples.
* Minor bug fixes.

Changes between hp48cc 1.1 - hp48cc 1.2

* Added a lot of examples.
* Added local variables to language.
* Added support for non-alphanumeric HP48 symbols in strings and identifiers.
* Minor fixes to the language syntax.
* Added raise to power operator `**'.

Changes between hp48cc 1.0 - hp48cc 1.1

* Fixes to documentation and package.
* Fixed minor bugs.