New rpc command name_filter (branch fastindex)

[khal]

New rpc command name_filter (regexp, max age, from, to, stat)
Syntax : namecoind name_filter [regexp] [maxage=36000] [from=0] [nb=0] [stat]

Allow to filter names :
- with regexp on names
- on name height : get names modified last 150 blocks ofr example
- get a fraction of names with from and nb values, like name_scan
- or get stats (only the number of names for now)

* list all unexpired names
namecoind name_filter

* list all names in the d/ namespace
namecoind name_filter "^d/" 0

* list names modified last 150 blocks
namecoind name_filter "^d/" 150

* count names modified last 150 blocks
namecoind name_filter "^d/" 150 0 0 stat

* list 20 names from number 100
namecoind name_filter "" 0 100 20

Patch : https://github.com/khalahan/namecoin/co ... be2acd8101

[phelix]

sweeet!