do not launch worker when READ_ONLY mode is enabled
set const when read_only mode is enabled
disable EDIT actions

- disable new, create, edit, update, destroy actions
add description for READ_ONLY mode
Merge pull request #203 from crest-cassia/read_only_mode

Read only mode
Merge branch 'Development' of github.com:crest-cassia/oacis into figures_displayed_on_scatter_plot