added a default value for Subsection parent field

adds a default value to Publication collection field

SLIM is now able to edit configuration from CLI, to start instances etc.

Now slim is able to create an instance, run make all, and start an interactive python without errors
refs #145

Able to :
- create/delete instances
- list instances
- run make %target% in all instances
- edit configuration given an instance name

refs #145

Deleted hardcoded condition that brokes standart field validation process

- Add an update feature to create_instance.sh script
- Updated webui plugin load instruction (running loader.start() in run)
- Updated the way EmCmponents handles EmGroup
- Updated the way EmFields handles EmClass
- Updated xmlfile translator according to EmComponent modification

	The UniqID datahandler has to call the datasource
	LeObject has to be able to determine wich parent class define its UID datahandler
	[NOT IMPLEMENTED] the datasource should be able to select with an abstract LeObject as target ( see #92 )

Adding a field to all non abstract classes to store in DB the name of corresponding LeObject subclass

- Added missing allowed_classes options to some references in em_test

- Modified again the em_test to fit with testing purpose
- First test on multi datasource query written
- debugging of query.py

- adding an EmClass to make a double link between indexes and texts
- adding subqueries infos to dump_infos method of LeFilteredQuery

- defining a new datasource named dummy2 in both tests conf and install/conf.d
- adding two class using the new datasource in em_test.py
 - index : abtract class representing indexes (two fields, name & content)
 - indextheme : thematic index, inheriting from index but with one more field "theme"

Using the conf to load emtests.pickle

- adds tests on filter parse & check
 - standart filters parse & check
 - relational filters parse & check
- bugfixes related to tests in query.py
- update the example and the test EM
- bugfixes in admin script

- the re for filter spliting is modified to better handle operators
- added leading & trailing space to some operators

Now a backreference is represented by a tuple(LeObject child class, fieldname)