FMSLogo Code

Add a regression test for when LABEL is given a word with line breaks.
MSWLogo ignored the line breaks, but after porting LABEL from win32 to wxWidgets, they are now honored.

Cleanup: Replace LogFontToWxFont with wxFont(LOGFONT).
wxWidgets has a constructor which does the same thing, so there's no need to duplicate its internal logic within FMSLogo.

Fix an unintentional change in behavior of LABLESIZE after porting it from win32 to wxWidgets.
wxDC->GetTextExtent(String) returns a bounding box that is larger than what ::GetTextExtentPoint returns.
This was found by the regression tests in label.lgo.

Fix a build break when compiling without precompiled headers

Enable setting the font face with SETLABELFONT on GNU/Linux.

Replace <section> with <variablelist> for the description of each menu item in the Workspace Editor.
Each <section> is rendered as a separate page, which is too much space for a one sentence description for something like Edit - Undo. This puts all items in the same menu on the same page.
This also removes some noise from the table of contents.

Add a screenshot of the workspace editor to the "Editor" section.

Change the documentation of items of the main menu from multiple <section> to a single <variablelist>.
A <section> is typically rendered as a separate page, which was too much for things like "Zoom - In", which only had a sentence of documentation.
Combining these related elements make the manual easier to navigate, particularlly by flattening the early part of the table of contents.

Rename createLabelFont to CreateLabelFont to better follow the code style.

Implement GetLabelFont() in pure wxWidgets.
This doesn't enable any new functionality, but it's a necessary step for doing so.