Jsonrewriter: balance_change type includes xrp balance
Jsonrewriter: added 'fee' effect type
Jsonrewriter: add balance_changer indicator
Jsonrewriter: fee effect should also have a balance field
Jsonrewriter: Separate fee from balance_change
New history page. See #347. Fixes #522, fixes #763, fixes #718.
Differentiate sell/buy offers by tfSell flag
Jsonrewriter: add currencies_affected arr to txn
History tab: Currency filter. See #347
History tab: css fix
Added scope.loadState. Show proper loading messages. Fixes #475
RpPrettyIssuer: default attr
JsonRewriter: effect.amount includes currency issuer
History tab: show currency issuers. Closes #347
Bump version to 0.2.24.
Add invite tab (empty).
Make all devDependencies normal dependencies.

This is a workaround for isaacs/npm#2369 and isaacs/npm#3250.
Update dependencies.
Add guidelines for contributors / issue tracker.
Add link to our own CONTRIBUTING.md.