RestApiv3: fixes
 - Made API fully CORS compliant (fixed OPTION method params)
 - Fixed new ReactionResource
Adding various helpers like HttpHelper (retrieve HTML, JSON or XML contents from urls); SerialHelper (improved serial ports communication); TcpHelper (tcp socket with timeout)
Quick fix: removed a not used dependency
Quick fix: right click on a plugin shows its GUI again. This is a temp fix, a better fix is to have multiple menus, one for plugin configuration and one to show its GUI
Fix PL-105: Close button on Login Form
SerialHelper: added feature to receive data in chunks of fixed size or ending with a custom string terminator
Payload check in trigger evaluation now uses a strategy pattern. Added also a BETWEEN_TIME feature that checks if a given time in format HH:mm:ss lays between a time interval in format HH:mm:ss-HH:mm:ss. It works also if the interval crosses day boundaries (midnight is in the middle of the intervall)
Some interface renaming
Fixed Core-332: Split and rename test plugin. Now the old test boundle is now named 'essential', a new 'simulation' boundle is created, logviewer and gui related plugins are moved to jfronted boundle
Chat plugin: small fixes
 - removed stale manifest.mf file
 - added plugin category into manifest