Optimize isFunction only when appropriate.

Closes #1929.
Test typed arrays are functions
Remove `reduce` error throwing

Closes #1858.
Support fromIndex in _.contains
Merge pull request #1962 from megawac/from-contains

Support fromIndex in _.contains
Adds a test case when we call _.pluck() to objects passing an undefined property as an argument.
Merge pull request #1971 from shinnya/feature/add-pluck-test-case

Adds a test case when we call _.pluck() to objects passing an undefined property as an argument.
better test method for missing properties in pluck
Merge pull request #1961 from jridgewell/remove-reduce-errors

Remove `reduce` error throwing
Merge pull request #1936 from jridgewell/isFunction_safari_8

Optimize isFunction only when appropriate.
Minor cleanup of #1936
Merge pull request #1974 from megawac/isFunction

Update isFunction tests
Use partial for defer.
Merge pull request #1977 from jridgewell/partial_defer

Use partial for `_.defer`
Clarify documentation.
Merge pull request #1979 from robbiehudson/clarify_after_documentation

Clarify documentation for _.after and _.before