Implement violations for most variable related rules
This is still limited to global variables. Looking inside functions will be implemented later.
Implements:
| Code | description |
|---|---|
| AL1 | Default builddir |
| AL3 | Quoted pkgname |
| AL4 | Quoted pkgver |
| AL5 | Empty variable |
| AL6 | Custom variables |
| AL14 | pkgname with uppercase |
| AL15 | pkgver with pkgrel |
| AL26 | _builddir |
| AL29 | pkgname in source |
| AL30 | Double underscore |
| AL31 | Variables with uppercase |
| AL32 | Unnecessary use of braces |
| AL35 | CPAN Variables |