added IInstallable interface and uninstall implementation for modules. Refactoring module installation to use interface still in progress.

Oqtane.Server/Modules/HtmlText/Scripts/HtmlText.1.0.0.sql

@@ -0,0 +1,19 @@
+CREATE TABLE [dbo].[HtmlText](
+	[HtmlTextId] [int] IDENTITY(1,1) NOT NULL,
+	[ModuleId] [int] NOT NULL,
+	[Content] [nvarchar](max) NOT NULL,
+	[CreatedBy] [nvarchar](256) NOT NULL,
+	[CreatedOn] [datetime] NOT NULL,
+	[ModifiedBy] [nvarchar](256) NOT NULL,
+	[ModifiedOn] [datetime] NOT NULL,
+  CONSTRAINT [PK_HtmlText] PRIMARY KEY CLUSTERED 
+  (
+	[HtmlTextId] ASC
+  )
+)
+GO
+
+ALTER TABLE [dbo].[HtmlText] WITH CHECK ADD CONSTRAINT [FK_HtmlText_Module] FOREIGN KEY([ModuleId])
+REFERENCES [dbo].[Module] ([ModuleId])
+ON DELETE CASCADE
+GO