[#16] Remove unnecessary prefix from class names.
[#16] Refactor duplicate code into a factory.
[#16] Use passed in path to set root of model.
[#16] Support specifying custom root for filesystem browser.
[#16] Avoid redundant unsetting of preset parent.
[#16] Fix indentation.
[#16] Correctly handle missing child error when indexing into list.
[#16] Return invalid index for missing item or parent.
[#16] Remove hard-coded root item in reset.
[#16] Avoid duplicate rows appearing when proxy model used.

Ensure proxy model calls source model rowCount implementation correctly.
[#16] Ensure each segment is loaded when setting a new location.

Also, refactor code to be simpler.
[#16] Fix incorrect name reference.
[#16] Improve path handling to deal with Linux roots better.
[#16] Display correct icon and name for root in path dropdown.
Merge pull request #20 from 4degrees/16_support_setting_root_of_filesystem_browser

Fix #16: Support setting root of filesystem browser