English grammar and spelling corrections

Major spelling and grammar corrections for English throughout the entire project.  Includes UI elements, log messages, Markdown files, and HTML files.  Common jargon has been adopted for widely-known UI conventions.

Nothing has been changed in code identifiers; only text visible to the end-user has been modified.  Additionally, (almost) no functionality has been changed.

A few additional log messages have been added in some places (e.g. an error is shown if GDB is not installed and the user attempts to debug a program).

The TextOutput widget was updated to preserve color in old entries that are to be faded.

This update makes the current translations very outdated.  They will need to be updated to coincide with the new English wording.