Property: remove type (fixes #264)

- Let Property inherit from IEntity instead of INamedEntity
- Redefine attributes name and definition on Property
- Adjust tests
ISection: update documentation comment
Section: creating a property with value
TestSection: c++11 style for loops
DataArray: polynomCoefficients takes a const ref

the setter DataArray::polynomCoefficients was taking a
non const reference to vector<double>.

This commit fixes this issue.
Merge pull request #265 from stoewer/property-type

Property: remove type
Changed signature of conditions to narrow parameter down to getter
Merge pull request #266 from balint42/validation_conditions

Changed signature of conditions to narrow parameter down to getter

LGTM
Changed signature of conditions to narrow parameter down to getter
Implemented validation for Block
new validation checks & validation for base entities and block

Also implemented test for block validation
Implemented validation and validation tests for DataArray
Implemented validation and validation tests for DataTag
Validation for dimensions, new checks and further check in base entity

Implemented validation for all dimension types, added new checks like ```isGreater``` and extended validation of the base entity
Implemented validation & test for Feature, corrected checks
Implemented validation & tests for File
Implemented validation & tests for Property
Implemented validation & tests for Section
Minor renaming of validation test methods
Implemented validation & tests for SimpleTag