The facelets cache management needs to be improved:

what is needed is:

- the possibility to clear the cache (e.g. when a theme is modified)
- the possibility to not cache a given facelet (e.g. when rendering non-static fragments)

currently the methods used in nxthemes are to:

- set a facelet modification date in the past - works only in dev mode, this is used for reloading JSF templates without restarting the server.
- add a ?timestamp=..... at the end of the url (this leads to memory leaks since every modification forces the facelet factory to create a new facelet, and the "old" facelets are not removed)

the main problem is that there is currently no good solution for rendering non-static fragments that should never be cached (e.g. the action fragment)

with the current facelets code the only solution is to create a new FaceletViewHandler, by extending SeamFaceletViewHandler and to create a custom FaceletFactory with better cache management functionality.

this means that references to SeamFaceletViewHandler would need to be updated in the configuration files.