* Update en_US.json
1. Severe mistake fixed: certain translation is previously incomplete.
* Update faq_en.md
1. Modified 1 entry for context consistency with lately merged en_US translation
* Update en_US.json
1. Attached colons to all Input Prompts as proposed.
2. Minor changes to translation expressions.
* Update en_US.json
1. Removed trailing periods on button texts