Introduced EqualPredicate.
Implemented the EqualPredicate class.
Addressed case-insensitive for equality of Parameter.
Removed IModelElement<TModel>.
Implemented ArticleElement.
Updated Experiment packages to v2.1.3.
Addressed argument guard condition that the name of Parameter should

start with '@'.
Addressed that constructors don't anything

except initializing files.
Modified the Condition text.
Addressed guard clause for empty string.
Fixed the 'Value' string accidentally changed by R#.
Changed IId to IKeyCollection.
Deleted ArticleElement.
Deleted ModelElementCollection.
Modified some types.
Revert "Introduced some interfaces to redesign."

This reverts commit 8d42eda2af917c52d74c9792f3c6d584dd5f99e3.
Addressed using Lazy<IUnitOfWork> instead of LazyUnitOfWork.
Deleted LazyUnitOfWork.
Merge pull request #28 from jwChung/delete-lazy-unit-of-work

Delete lazy unit of work
Removed repository properties from UnitOfWork.