Release version 3.0.0

• Add four memory buttons in the Read text screens (thanks to @woheller69).
• Add "nicer" image buttons (thanks to @woheller69).
• Add status fields to each screen.
• Add the ability to create wave files from input text and clipboard text.
• Allow selection of non-local documents in the file choice screen.
• Change the application settings menus to play sample text.
• Change the application to follow the system theme where possible (thanks to @woheller69).
• Fix an error where large text files could not be synthesized.
• Fix an error where the application did not properly release the audio focus.
• Improve the performance of text-to-speech playback and file synthesis.
• Improve voice selection in the application settings.
• Merge the Read from files and Write to files screens.
• Other fixes and improvements.