Achapman/ch15705/trading api improvements

[nuevoalex]

• Simplify API by removing unused (in our code base) and redundant methods
• Simplify / fix the fill order loop in trading
• Add ability to ignore owned shares when creating / filling / trading
• Add ability to trade in terms of total cost instead of shares
• fxpAmount -> amount
• displayPrice -> price

[adrake33]

Looks like Travis is also complaining about several unused function params in Trade.sol.

[codeclimate[bot]]

Analysis results are not available for those commits

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[adrake33]

There are some parameter mismatches in TestFixture.ts that still need to be resolved.