New auto update feature

– Removed support for OneUpdater. From now Alfred PDF Tools relies on
Alfred-Workflow library for self-updating.
– Significant code improvements for better stability and maintenance.

Author: xilopaint

Alfred PDF Tools.alfredworkflow

@@ -17,16 +17,18 @@ Download the workflow file from [GitHub releases][2] and install it by double-cl
 * `Optimize`: Optimize the selected PDF files by entering the intended resolution of the output file (150 dpi is set once no value is input). The document will be improved on the process with increased contrast and text straightening. Invoke Alfred and type the keyword `progress` if you want to track the optimization process;
 * `Encrypt`: Encrypt the selected PDF files by entering a password;
 * `Merge`: Merge the selected PDF files. Use the `⌘` modifier key if you also want to move the source files to Trash;
-* `Split`: Split the selected PDF file either by page count or file size (use the `⌘` modifier key in the latter case);
-* `Slice`:  Slice the selected PDF file in multiple files by entering page numbers and/or page ranges separated by commas (e.g. 2, 5-8). For a single file/slice use the `⌘` modifier key.
+* `Split by Page Count`: Split the selected PDF file by page count.
+* `Split by File Size`: Split the selected PDF file by file size.
+* `Slice in Multiple Files`: Slice the selected PDF file in multiple files by entering page numbers and/or page ranges separated by commas (e.g. 2, 5-8).
+* `Slice in a Single File`: Slice the selected PDF file in a single file by entering page numbers and/or page ranges separated by commas (e.g. 2, 5-8).
 
 ## Contribute
 
 To report a bug or request a feature, please [create an issue][3] or [submit a pull request][4] on GitHub.
 
 ## Credits
 
-This workflow relies on [PyPDF2][5] library currently maintained by [Phaseit, Inc.][6], [Alfred-Workflow][7] library by Dean Jackson, [K2pdfopt][8] by Johannes Buchnerand, [Send2Trash][9] by Virgil Dupras and [OneUpdater][10] by Vítor Galvão.
+This workflow relies on [PyPDF2][5] library currently maintained by [Phaseit, Inc.][6], [Alfred-Workflow][7] library by Dean Jackson, [K2pdfopt][8] by Johannes Buchnerand, [Send2Trash][9] by Virgil Dupras and [docopt][10].
 
 ## License
 
@@ -41,5 +43,5 @@ This workflow relies on [PyPDF2][5] library currently maintained by [Phaseit, In
 [7]:https://github.com/deanishe/alfred-workflow
 [8]:http://www.willus.com/k2pdfopt/
 [9]:https://github.com/hsoft/send2trash
-[10]:https://github.com/vitorgalvao/alfred-workflows/tree/master/OneUpdater
+[10]:https://github.com/docopt/docopt
 [11]:https://opensource.org/licenses/MIT