1.5 Lock Attributes, FTP downloader and ZIP decompressor

### Features
- [Lock attributes functionality](https://github.com/ho-nl/Ho_Import/#lock-product-attributes-in-backend).
  - Add product attribute ho_import_profile and set the profile used to import the product.
  - If an import has the <lock_attributes> option set all the attributes will be disabled on the product-page.
  - Extra text is added to the attribute note: "Locked by Ho_Import".
  - Be able to handle multiple attributes, fixes
- Added [file decompressors](https://github.com/ho-nl/Ho_Import/#decompressors), zip supported.
- Cleaned up downloaders and added [FTP downloader](https://github.com/ho-nl/Ho_Import/#ftp-example-white_check_mark-low-memory)
- Implemented [getAttributeId](https://github.com/ho-nl/Ho_Import/#getattributeid), deprecated getMediaAttributeId
- [getFieldLimit](https://github.com/ho-nl/Ho_Import/#getfieldlimit) implemented, implements array_slice

### Fixed
- Image mover didn't work with 2G, works with 2048M
- When parsing XML, sometimes array keys were returned, resulting in wrong store view data.
- Solve problem with the getFieldMap and ampersand. [#32](https://github.com/ho-nl/Ho_Import/issues/32)
- Issue with the formatField method, was unable to handle arrays for input
- Fixed a problem where you couldn't return 0 for getFieldCounter.
- Copyright to 2014

[Full changelog](https://github.com/ho-nl/Ho_Import/compare/1.4...1.5)