SignManager is an all-in-one sign editing plugin allowing players to copy, paste, and modify signs that have already been placed. Editing a single line on a sign is as easy as typing a command and clicking the sign to modify.
This plugin was compiled with java 8.
Features 
Modify placed signs.
- Instead of rewriting an entire sign, you can replace single lines with a simple command: /sign set
Copy and paste signs.
- Everyone is given a SignManager clipboard for copying and pasting signs.
- There is no limit to how many times a sign may be pasted.
Permission checking.
- It's safe to let players use features from this plugin since it checks build permissions before applying changes to signs.
Colorful signs.
- Convert color codes (using the & symbol) to colors for players with the signmanager.colors permission.
- Great donor perk.
Commands 
/sign set <line number> <text>
- Set a specific line number of a sign
- Example: /sign set 2 &3Hello!
/sign copy [optional: <pastes>]
- Copy a sign to your SignManager clipboard. Click on another sign to paste.
- Example: /sign copy
- The optional 'pastes' argument is how many times you would like to paste a sign.
- Example: /sign copy 3
- (Paste the copied sign 3 times)
- Setting the pastes argument to a negative number allows you to paste unlimited times.
- Example: /sign copy -1
- (Pastes the copied sign until the server restarts or you do /sign cancel)
/sign copyline <line number> [optional: <pastes>]
- Copy a specific line to your SignManager clipboard. Pastes will only include the copied line.
- Example: /sign copyline 3
/sign cancel
- Cancels sign copying/pasting and clears your SignManager clipboard.
Permissions 
Players with op automatically have all necessary permissions to use this plugin and its features.
- signmanager.colors
- Allows players to use & color codes on their signs
- signmanager.command
- Gives access to the /sign command
- signmanager.*
- All SignManager permissions