Now querying IA to search in gutenberg collection

Changed search query from deprecated PG to IA(archive.org) with
json output format.
TODO:
- parse and fetch entries from json output
-
Updated request for more info on books
Changed etext_id type from int to string

Identifier type in archive.org is string
Rewrite gutenbergweb to handle(kludgy) archive.org

Now it somehow supports search and downloading from archive.org:
- search thru IA json api, fixed type to mediatype
- download from standart-looking path on IA by known book identifier

TODO: bugs
BUG: fixed unexpected indent
simple changes to approach query parameters
BUG: fixed https://github.com/rlevi/mgutenberg/issues/1

Added handling for unset fields into book description
enabled search on whole archive.org(PG included:)
added gettext around mediatype, just in case
More rows in search result
Merge branch 'master' into t-archive.org-search

Conflicts:
	mgutenberg/gutenbergweb.py
Query archive.org only for texts
Renamed gutenberg tab and fixed readme
Fixed query for specified pageno of search result
BUG: fixed "More..." button reaction

fixed action on "More..." button pressing: entry[4] type was changed,
but not NEXT_ID comparision.
Merge branch 't-archive.org-renaming' into t-archive.org-search
updated debian changelog
BUG: fixed json library miss for python 2.5

- Added python-simplejson to package dependencies
- Added hack to use simplejson if json is not available
Revert "BUG: fixed "More..." button reaction"

This reverts commit 8545ac5d76731f94db9992dc3b00d40c3cc8b158.
BUG: fixed "More..." button reaction, once more

python 2.5 fails to int("blahblah")