Resizing flot plots and deleting works

* added plot control sidebar (legend and deleting plots)
* deleting flot plots works
* resizing implemented with own flot plugin
** original didn't work somehow (r is undefined?)
** resizing works quite well now
* plot color assignment is better now (side effect of new code for deleting ;))
Flot resizing improvements, closes #51

* fixed regression: showing plots after hiding them is possible again
* resizing works for entry view now, too
* placeholder is not resizable anymore
* buildout fix for nosetests, works now
* some improvements to styling
* removed plot area size hack
Fixed disabled flot area and minor improvements

* fixed regression: plot was not enabled when adding plots to previously
    disabled plot area
* plot button is deactivated now when less than 2 rows are selected
* code formatting
highlight selected rows in different colors
resizable plot control, fixed plothover / click regression

* plot control is resizable now
* plothover / click didn't display anything because of structure changes
* moved plotmessage / hover clickbox to span inside of plot display

    ** fixes regression and works better when resizing other stuff
Refactored app creation, fixed bug when creating an empty set

* splitted yamoda.server module in
** login manager
** jinja filters
** default settings
** app creation (__init__)
* app is created by a function now
* function for loading jinja filters from a given module
* better logging on server start
** show config and config file path (if used)
* moved runserver module

bug fix:
* Exception on empty set creation: check for empty data_id string now

misc:
* Readme update with gunicorn example
* moved buildout config for database modules to separate cfg file
Added calculated param to AugQL

* added parcon parser for Python expressions
* AugQL parser understands single calculated param lines at the end
** changes needed to support multiple 'calculate' clauses
Calculated columns support in AugQL works now

calculated columns:

* expressions in calc columns are delimited by ; now
* multiple calculate clauses are supported correctly now
* serializer / deserializer works for calc columns
* tests for parser extended for calc columns
* tests for serializer / deserializer

other:

* added 'meta' package to README
* initdb repaired and moved
Compile (safe) python expressions to functions

* Whitelist checker for expressions
* create_function_from_ast which translates expression AST to a lambda with arguments
  derived from the free variables in the expression

* removed meta source dump from serialization because of problems.
** now: serialize the original expression and parse it again on load (should be improved later)
test invalid expressions, return args from make_function function
Calculated columns now integrated in search result

* dataresult table extended for calculated columns
* "calc" and "calculate" allowed as keywords for calc columns in AugQL

expression improvements:
* restricted function set now allowed in python expressions (currently
  only math functions (-> checked by WhiteListExprVisitor))
* allow some more nodes like Pow or BoolOp (Or, And, ...)

other:
* more and better expression parsing / compiling testing
* much faster get_entries functions
Cond. expressions and strings for expr. parser

* Python expression parser understands strings and conditional
  expressions now
* added helptext for calculated columns