Rename existing_precheck()
Refactor build.build()
Move dependency detect code to package.dependencies()
Fix broken negate all in .gitignore
Add clean_chroot to configuration
Refactor chroot.py

Changed the way packages are installed into the chroot
Change arch_list_from_path argument name
Add dependency_list to pkgbuild.py
tests/util.py: Increase random string length to 16
tests/util.py: Fix test project name
Refactor package.py

Once again, package.py has been refactored. The main change is to have each
package object to include info for all architecture targets. It would have been
needlessly complex to manage each separate package object for each arch target
when building a dependency graph of packages.

Other changes include:

* Rename _move_source_to_stage() to stage_package_source_binary().
* Rename _move_package_to_stage() to stage_package_binary().
* Change all boolean return values into proper exceptions.
* Add getter functions for getting properties of a package arch target.
* Add find_local_package()
* Add find_name_in_list()
* Add locate_package() for finding a package locally or in AUR.
* Rename create_list() to get_list()
* Add the dest argument to get_list()
* Add the build_order() function for ordering the packages based on a
  dependency graph.
* Added the "any-package" to the min_test_project for testing using the "any"
  arch target.
* Add three new tests for test_package.py