Removed logback dependencies

* Logback has been added in the core JAR whereas it should remain in a
client app
* Fixed dandelion/issues#118
Renamed Configuration to Parameter
New way to store possible configuration

* ConfConstants class replaced by new enumeration: Configuration
* Linked with dandelion/issues#113
Configuration processing refactored

The whole configuration system has been refactored to offer the
possibility to enable configuration:
* from properties file
* from JSP tags/attributes
* from Thymeleaf attributes
* programmatically
Others changes:
* Old TableProperties object renamed to TableConfiguration
* Almost all configurations have been removed from the HtmlTable object
and are now stored in a new Configuration enumeration. This is now the
only entry point when accessing any configuration.
* AbstractProcessor and lots of implementations added : all processors
contain the actual processing applied on each Datatables
* Old PropertiesLoader class (used to load default and custom
properties) replaced by a new extensive system: default properties are
loaded using a ConfigurationPropertiesLoader and custom ones are
defaultly loaded using the same loader. It is possible to write a custom
loader (e.g. ConfigurationJsonLoader) and use it using the new
DatatablesConfigurator class
* All keys renamed in the default properties file
* JSP tags and Thymeleaf processors now use the new configuration
mechanism
* New confGroup table attribute, allowing to activate a "configuration
group" on a local table
* New unit tests (that has to be refactored)

Notes:
* lots of unit tests are missing!
* export links generation and plugins activation is still broken
* the cssClass and cssStyle attributes haven't been refactored with the
new configuration mechanism
* the Thymeleaf TableFinalizerElProcessor still need to be refactored
using the new configuration mechanism
Reflections dependency temporarily removed

Due to classpath conflict preventing all integration tests to run