move FLAG_SECURE to PassphraseRequiredMixin

Fixes #1402
// FREEBIE
Merge pull request #1614 from mcginty/contact-list-security

move FLAG_SECURE to PassphraseRequiredMixin
add section about submitting useful bug reports
remove ReviewIdentitiesActivity

// FREEBIE
temporarily disable encrypted backup

// FREEBIE
Merge pull request #1631 from mcginty/disable-encrypted-export

temporarily disable encrypted backup
Fixing race condition and other mistakes. Fixes #1603.

// FREEBIE
Merge pull request #1630 from mcginty/remove-keys-list

remove ReviewIdentitiesActivity
Remove unused files.

Fixes #1522

// FREEBIE
Replace XML serializer in plaintext export

Fixes #342

- using regex pattern/matcher to escape chars below 0x0020 and
  above 0xd7ff
- using String.Replace to escape XML entities
- changed XmlPullParser from Xml.newPullParser() to
  XmlPullParserFactory parser to fix import on GB
Revert "change out key cached icon to be more unique"

This reverts commit d6d76fa95315068ab5457b23fb4908c4a8586982.
stop using undocumented broken sqlite function

Fixes #791
// FREEBIE
don't e164-ize shortcodes
new version of libphonenumber
canonical address db refactor
add testing
Revert "stop using undocumented broken sqlite function"

This reverts commit b6e1946ee9b48f47a02e2c4b114aba187a59d78d.

Conflicts:
	library/build.gradle
	src/org/thoughtcrime/securesms/database/CanonicalAddressDatabase.java
remove old-new tests
Revert "remove old-new tests"

This reverts commit 5438cbde7e6386a30f4d6cef4680baeb800af8d7.
Revert "Revert "stop using undocumented broken sqlite function""

This reverts commit c60a9152bbb1695d72f6c0b025290a5d378032ff.