Fix #2853. When removing a class, also log its contained methods

[tinchodias]

I propose this fix/workaround to tackle this issue.

[tinchodias]

Included a test, but you can also evaluate this code and see the result in the Code Changes browser:

clazz := Object subclass: #Clazz
	instanceVariableNames: ''
	classVariableNames: ''
	poolDictionaries: ''
	package: 'Martin'.

1 to: 7 do: [:index |
	clazz compile: 'inst', index asString.
	clazz classSide compile: 'class', index asString ].
clazz removeFromSystem.

[tinchodias]

Epicea supports nesting events (e.g. in refactorings), so it could be an improvement to this fix to nest al method removals inside the class removal. This can be reported as another issue.