This will restore any of the previously loaded files when restoring the
context.

   ** I'm sorry if this causes a bunch of files to open on you **
   ** initially, since we failed to prune them in the past.    **

Once you close them (and wait a few seconds for the reclamation to
happen), they shouldn't come back.

If it gets really annoying, and you want to have a clean slate, just
remove everything in ~/.local/share/gnome-builder/drafts/

I think what we want to do long term, when closing with unsaved files
is to determine which of these use cases we want.

 1) save the changes to a draft, but leave the real file untouched.
 2) just save the file to the original file.

This gives us the plumbing we need to opportunistically release buffers
from the buffer manager when they are no longer viewed.

Still work in progress, but this can land as it's own patch.

No need to inherit from IdeObject, the context is inconsequential.

Typically I use LGPL-2.1+ for shared libraries. However, due to the
nature of libide being the "guts" of Builder, I do intend for this to
be GPL-3.0. Additionally, it simplifies what we can include in the
library without worrying about staying LGPL safe.

Exceptions will of course be made for upstreaming into libraries such as
GtkSourceView. Just ask if you want something in particular.

This will probably need some fine tuning, but this gets us started.

This keeps code paths more similar to the normal file load path.

Enforce maximum file size fo 10 Mb for now. You can disable this by
setting the IdeBufferManager:file-size-max property to zero in your
scripting environment if you need larger files.

We can raise this later, but we are not very well suited to open very
large files like SQL dumps and files of that nature.

We can use the back-forward-list to determine the last insert mark
position and restore it when we load the buffer.

Query the global IdeBackForwardList to fetch the most recent insert
mark location.

This allows IdeSourceView instances to attach word completion using all
buffers loaded in the IdeBufferManager.

This method will return a newly allocated GPtrArray with all of the
loaded buffers as elements.

Only a reference to the GPtrArray is returned (transfer container), but
the container has a reference to the buffers.

Simply release with g_ptr_array_unref().

If the IdeFileSettings dictate that we should trim trailing whitespace,
then trim whitespace from lines that are marked as modified by the
IdeBufferChangeMonitor.

Limiting changes to only these lines helps avoid those giant diffs where
all you did was trim trailing whitespace.