docs: fixes some fpdoc links by using the full path syntax.

fpdoc is very buggy when it comes to cross-linking help topics. So by
changing the link URL to the fully syntax, we try and help fpdoc along.
This has limited success though, but every bit helps.
docs: added the remaining fpGUI units to the fpdoc project file.

Even though they are not all document, having them in the INF file is
very handly for method, event and method signature lookups.
docs: disable protected methods from the documentation.

I first what to document the Public and Published properties and methods,
as those will be the most used by fpGUI end-users. The protected methods
can be documented at a later stage.
docs: adds new docs for fpg_grid.pas unit.
docs: fixes or adds the encoding attribute for fpdoc XML description files.
docs: fixes the <link> tags to use the full fpdoc link syntax.
docview: fixes a grammar error in the docs
docview: Fixes a bug where URL links where not handled correctly.

When we detected know web browser names, we had to only use the URL part,
not the original program+url text. DocView lets the OS choose the
web browser.
docview: fixes grammer error in code comment
Adds Chrome and Chromium support to fpgOpenURL()