fix the bug of accessing attachment without checking existence

modify img name representation

modify parsing rule as CP_NS/CP_WS/FB_NS

let feature annotation block can be null then will send "Others" to server

Merge pull request #8 from yuan310979/dependabot/bundler/websocket-extensions-0.1.5

Merge pull request #7 from yuan310979/dependabot/bundler/devise-4.7.1

Merge branch 'master' of https://github.com/yuan310979/cgmh_annotation

change upload redirect path

Bump devise from 4.6.2 to 4.7.1

Merge pull request #6 from yuan310979/dependabot/bundler/rack-2.2.2

Bump websocket-extensions from 0.1.3 to 0.1.5

Merge pull request #5 from yuan310979/dependabot/bundler/nokogiri-1.10.9

Merge pull request #4 from yuan310979/dependabot/bundler/loofah-2.5.0

Merge pull request #3 from yuan310979/dependabot/bundler/rubyzip-1.3.0

enlarge display area & modify upload parsing rule