README: Add not about dependencies
app.py: Rename conf.pkg_input to conf.input_packages
logger.py: Fix message newline handling

Properly handle newlines at the start of a message.
util.py: Use expac for getting package information

Rename pacman_package_in_database() to
check_package_in_pacman_local_database(). The
check_package_in_pacman_sync_database() was also added.
package.py: Add parent argument to location functions

The parent argument tells the location functions that the package is a
dependency of parent. This allows the package to be located in
{parent}-{aur}dep-{package}.
package.py: Add PackageWrongVersion exception

PackageWrongVersion is now raised when a package is located, but the wrong
version is detected.
package.py: Add support for "-aur" name packages

Packages that are pulled from AUR will have the "-aur" suffix added to them to
indicate the package is from AUR. Dependencies from AUR will be named
{parent}-aurdep-{package}.
package.py: Fix duplicate packages in package list
package.py: Remove optdepends from dependency script

Optional dependencies are optional.