New `show` method, implement `hessian` for more types

Highlights:

• Add show method that circumvents bounds errors (#271)
• Implement hessian for more types (#269)
• Improvements in inference and compile time (#274, #276)

Scaled fixes

Merge pull request #267 from kdw503/dwk/eachvalue_iteration

test and fix iteration error of ScaledIterator

Improve inferrability of FixedExtrapolation

Merge pull request #259 from JuliaMath/teh/fix_258

Improve type-stability of FilledExtrapolation (fixes #258)

Fix eltype, improve gridded indexing performance

Merge pull request #257 from JuliaMath/teh/perf_gridded

Improve performance of gridded interpolation for knot-ranges

Extrapolation in monotonic

v0.10.3

Support for Flat, Line and Throw extrapolations for monotonic interpo…

Fix knot lookup, warnings

Update README.md (#247)

Added some info about how to deal with `missing`.

Fix precision-induced boundscheck failures

Merge pull request #245 from JuliaMath/teh/fix_#244

Avoid numerical-precision failures of bounds checking (fixes #244)

Monotonic interpolation

v0.10.0

Merge pull request #243 from JuliaMath/mateuszbaran-monotonic-interpo…

Fixes for gradient! and signature generalizations for convenience "constructors"

Merge pull request #241 from JuliaMath/teh/fix_230

Generalize signatures of convenience constructors

Throw informative errors

Merge pull request #233 from JuliaMath/teh/fix_232

Clean-ups to extrapolate