SoupCache: do not store headers on cache index
@svillar
Submitted by Sergio Assigned to libsoup-maint@gnome.bugs
Link to original bug (#665884)
Description
Currently the message headers are stored in the cache index file. The reason is easy, the code is simpler. There are some drawbacks tough:
- memory usage: all the resource headers are loaded in memory always even if they are never used
- cache load/dump times: we need to serialize/deserialize all the message headers to store the cache index file always