client, Unix: remove #ifdef on HAVE_DIRENT_H
BOINC web site: add Android/PTG link
db_dump: include badges in XML stats export

I did this by including list of badges in the tables.xml file,
and writing the list of badge assignments to 2 new files,
badge_user.gz (for users) and badge_team.gz (for teams).

I considered including the badges within the <user> and <team> elements.
However, this would require enumerating the badges for a particular user
within the enumeration of users, which doesn't work;
only one enumeration can be active at a time.
Plus it would be less efficient, and db_dump already takes
a half hour on a big project.
client: fix bug in set_cc_config RPC saving value of <start_delay> option.
- CC_CONFIG.start_delay is a double, not an int, so CC_CONFIG::write() must use %f format rather than %d.