** Added "MaterialReply" -entity into material plugin (represents user's
reply into a single material)
** Removed help, hint and type from QueryField because help and hint
columns are used in render time only and thus are not part of the field
model and type because type can always be resolved from implementing
class 
** Added material column into QueryField because QueryField should
always be bound to some material
** Changed workspace-html-material view's save button to appear only
when user is logged in
** Removed create method from QueryFieldDAO because QueryFields should
not be created directly 
** Added QueryTextFieldController
** Refactored MaterialReply -> WorkspaceMaterialReply because Materials
can be used in multiple workspaces and the replies should not be shared
among different workspace materials
** Added entities into materialfields plugin descriptor
** NotEmpty validator can not be used with Boolean
** Added WorkspaceMaterialTextFieldAnswer entity and DAO (Represents
user's answer into a material text field
** Added controller for workspace material field answers
** Initial draft of html material answer saving (works only with text
fields and does not load saved answers)
Merge branch 'FTR-4' of https://github.com/otavanopisto/muikku.git into
FTR-4

Conflicts:
	muikku-core-plugins/src/main/java/fi/muikku/plugins/materialfields/dao/QueryTextFieldDAO.java
	muikku-core-plugins/src/main/java/fi/muikku/plugins/materialfields/model/QueryTextField.java