Add Trezor to wallets
small fixes to previous commit
Drop list of hardware wallets in "Secure your wallet"
Add @arvicco in the list of contributors for his work on Russian translations
Remove duplicate "how" from sentence (thanks @astern7!). closes #561
Fix OP_RETURN misconception

Satoshis sent to an OP_RETURN-using output are simply unspendable; they
do not go to mining fees.
Remove OP_1NEGATE mention

Never used in standard transactions
Merge pull request #545 from bitcoin/trezor

Add Trezor to wallets
Add Texas Bitcoin Conference (fixes #557)
Only list Bitcoin-related events from meetup (fixes #558)
Add "Bitcoin Law" event (fixes #565)
Fix a typo
Update sl, hu translations
Add "Bangkok Bitcoin Expo" event (fixes #571)
Fix deprecated use of gravatar_id with the GitHub API
Merge remote-tracking branch 'remotes/arvicco/master'
Update events (fixes #551 #568)