DASHB-582: Negative numbers of session usage
PLGEDT-44 Extract interface for breakpoint manager
PLGEDT-44 Add an interface for a breakpoint renderer
PLGEDT-44 Add resources for breakpoint marks
PLGEDT-44 Add gutter constants
Gutter annotation renderer: Lower log level to debug
PLGEDT-44 Use Gutters constants in GutterAnnotationRenderer
Create an abstract implementation of embedded document
Set file on EmbeddedDocument
PLGEDT-44 Implement breakpoint renderer
PLGEDT-44 Add an interface for styling lines
PLGEDT-44 Add a 'debug line' style
PLGEDT-44 implement BreakpointManager
Add information on the gutter click event
PLGEDT-44 Add a HasLineStyler interface
PLGEDT-44 EditorWidget has a line styler
PLGEDT-44 Add a BreakpointRenderer factory
PLGEDT-44 Embedded editors implement HasBreakpointRenderer
PLGEDT-44 Bind BreakpointRenderer and BreakpointManager
PLGEDT-44 Editor widget extends HasGutterClickHandlers