Merge pull request #37 from marksteward/master

Proper card-adding interface
Validation for card IDs
Fix calendar insecure content
Update comment for card form
Dynamic cost of hacking poster
Source tweak
link 'join today' on the cost of hacking page
Merge pull request #38 from dekstop/master

Link 'join today' on the cost of hacking page
Rewrite members area to try and reduce queries
Merge branch 'master' of github.com:londonhackspace/hackspace-foundation-sites
Link Bitcoin donation address to to blockchain.info

Linking to the blockchain.info page for the Bitcoin donation address makes it easier for people using mobile wallets to donate - there's a QR code to scan.
Merge pull request #39 from sde1000/patch-1

Link Bitcoin donation address to blockchain.info
adding 'cost of hacking' link to signup page
Merge pull request #40 from dekstop/master

adding 'cost of hacking' link to signup page
Fix non-SSL content
Make image visible
Block Visa UID
Update bitcoin address to new Coinbase account
Support spaces in references
Readme update