Hide lookup key button explicitly, previously it was still visible after downloading a key
Fix potential ClassCastException

Implemented the fix suggested by zjw in pull request #463
https://github.com/k9mail/k-9/pull/463

Fixes issue 5928
Merge pull request #465 from jca02266/master

Changed for Android Gradle plugin 0.9
Fix typo
Remove some unused strings
Ignore missing translations
Don't use hardcoded package in namespace
View class referenced from a layout should be public
Don't reuse IDs
Remove deprecated resource attributes
Remove unused resources
Fix whitespace to get rid of ExtraText lint warnings
Suppress warning about "inlined API"
Fix PxUsage warning
Fix SpUsage lint warnings
Fix (bad) manual boxing

Fixes UseValueOf lint warning
Add missing inputType attribute
Extract hardcoded string from layout
Explicitly use the default locale
Merge branch 'fix_lint_warnings'

Fix some lint warnings