The requiring of a package's main module is now decoupled from package
activation. Non-deferred packages will always be required before the
panes are deserialized. This allows the package to register any
deserializers for objects displayed in the panes.
Deferred packages can contain a 'deferredDeserializers' array in their
package.cson. If we attempt to deserialize an object with a deserializer
in the list, the package's main module will be required first so it has
a chance to register the deserializer. But the package still won't be
activated until an activation event occurs.
We may want to add an additional optional hook called 'load' which is
called at require time. We would not guarantee that the rootView
global would exist, but we could give the package a chance to register
deserializers etc. For now, registering deserializers is a side-effect
of requiring the package.
Markdown preview was overflowing because the min-height of flexbox
items is automatically set to min-content. Setting it to 0 ensures that
the item doesn't expand beyond its flex size. Moving this styling to
atom.css ensures that people don't have to work too hard to fit
their views into panes.
Modal dialogs can be presented while other modal dialogs are already
being displayed. Previously, dialogs were always displayed in the order
they were requested. But say you have two untitled buffers in a
pane and you close all items… You'll display prompt dialogs for both
buffers asking the user if they want to save. If the user answers yes
to the first dialog, they should see the path selection dialog before
they see the save prompt for the second buffer.
This commit uses a stack of queues to store deferred dialogs and allow
dialogs presented by the dismissal of another dialog to take precedence
over other pending dialogs.
Buffer keeps state about the value with which it fired the last
modified-status-changed event so that it doesn't fire it twice with the
same boolean value. Every piece of code that triggers the event also
needs to set this state, so now everything goes through the
`triggerModifiedStatusChanged` method.
