add bitcoin receiving address to profile
log changes to participants table
add db rule to log changes to bitcoin_address
test bitcoin.json, validate bitcoin address, and move migration to branch.sql
refactor bitcoin form to make it inline on profile page
fix javascript issue that triggers edit form on a click event (bitcoin address)
Remove forgotten "is None".

user.ANON is a property that returns bools only.
close #1292
make this a link
Add danishtariq to security.txt for #1536
Fix future division in fraud simplate brought by #1529.
Merge pull request #1544 from gittip/fix-simplates-division

Fix future division in fraud simplate brought by #1529.
Bump version to 10.1.28
Bump version to 10.1.28-dev
Merge branch 'master' into fix-sign-out
Add test to confirm the fix.
Alter homepage caching not to cause InternalError.

The change is based on the following test. You need two separate
connections to the db. On the first run:

    create table a (i int4);
    insert into a (i) values(1);
    begin;
    delete from a;

Now on the second connection run:

    select * from a;

That does not block and returns "1". The thing is that we can freely
update the table "a" in a transaction and not block parallel reading
of the original data in the table.

Open question: Does Heroku have some autovacuming on? If not we should
turn it on or the homepage tables will grow beyond bounds (the deleted
data is expunged only by a vacuum run).
Fix failing test (tables no longer recreated).
fixes https://github.com/gittip/www.gittip.com/pull/1437#issuecomment-24786372
Merge pull request #1524 from gittip/fix-sign-out

Remove forgotten "is None".