Bumped version number to 0.20.0-SNAPSHOT
Updated contributors
Improved function `ifElse`
Implemented conditional operator `a ? b : c` in expression parser
More unit tests added
Some more unit tests
Add fromPolar and math.complex with polar input #76
Switched to module `decimal.js` for BigNumber support, instead of `bignumber.js`.
Add toPolar method #76
Add constructor support for polar and {re:..,im:..}  Fixes #76
Updates and fixes to work with a different BigNumber instance per math.js instance
Simplification of function digits
Removed preliminary rounding of results of `det`
Fixed broken unit test
Merge pull request #155 from finnp/develop

Add support for polar coordinates in complex numbers
Merge remote-tracking branch 'origin/develop' into develop
Removed dependency on global `math` from `Complex`
Implemented `BigNumber` support for function `det`
Fixed #156: Fixed support for element-wise comparisons between a string and a matrix
Changed configuration option `decimals` to `precision`