Added variants related interfaces
Added OptionValue implementation
Fixed the concept of presentation for optionValue
Fixed the concept of name for optionValue
Added Option implementation
Improved naming for variability related options (from availableOptions to variabilityOptions)
Added VariableTrait
testing with hhvm-nightly
Fixed trait method import
Added Variant and improved VariantInterface
added identifiable interface on variation related interfaces
Added interfaces related to the attribute models
Added Attribute implementation
Added AttributeValue class
Removed some duplicate code and minor cs-fixes
fixed Attribute subject and attribute value. Added attribute subject trait
Tested and fixed AttributeSubjectTrait
Added products models and interfaces
Merge pull request #10 from lmammino/1-create-product-related-models

merge #10 Create product related models (lmammino)

This PR was merged into lmammino:master branch.

Discussion
----------

|Q            |A  |
|---          |---|
|Bug Fix?     |n  |
|New Feature? |y  |
|BC Breaks?   |y  |
|Deprecations?|n  |
|Tests Pass?  |y  |
|Fixed Tickets|#1 |
|License      |MIT|
|Doc PR       |   |
                   


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Commits
-------

58032abb36b038c3b14bcb5e16f8c5726a875e14 Added variants related interfaces (lmammino)
90fe1c56b2d6e82ad93394b3f03c7d916ccd793a Added OptionValue implementation (lmammino)
1cde76211e5a04bd9f6795752b0f663b0e2410dc Fixed the concept of presentation for optionValue (lmammino)
7e2b390888b82e8426c40d0f42287db55c88df73 Fixed the concept of name for optionValue (lmammino)
f598776a3f732d51884b772a09114e6f68b60381 Added Option implementation (lmammino)
d2df8e6769db2bf68c40e32dff998b5e9f9dec8a Improved naming for variability related options (from availableOptions to variabilityOptions) (lmammino)
2404c5dab29f6a75ec3f7538c6e42612ab9fe458 Added VariableTrait (lmammino)
636bfdb3bcc7285cec41ef7bdefb51aece93ac23 testing with hhvm-nightly (lmammino)
660eab5b504af38ea4a36a157fe43009e6bab9d0 Fixed trait method import (lmammino)
95408ca09b043e0e252f3f7ee909b07fb6a790e1 Added Variant and improved VariantInterface (lmammino)
557bd9a382dcc9632e86452fef1ee9708a17f929 added identifiable interface on variation related interfaces (lmammino)
4189fbb752be3e226ff29594839d51c2e77c95f2 Added interfaces related to the attribute models (lmammino)
1e506ede979595b546f1a96dd04f0297d35071ee Added Attribute implementation (lmammino)
bb92b975e57251165d96a16ab03bb9ff910ecf26 Added AttributeValue class (lmammino)
e351c53967b3a6939b04c38aadbbbec23dd22738 Removed some duplicate code and minor cs-fixes (lmammino)
598851d0252cfb0e591457ce2b275e5bf0bbaed5 fixed Attribute subject and attribute value. Added attribute subject trait (lmammino)
1e3b5251d013dea40f61c95ec964598cca7640c8 Tested and fixed AttributeSubjectTrait (lmammino)
9dd476fbba6cbacd4e5f2125a2e7c115acdecbdd Added products models and interfaces (lmammino)