Refactoring Objective to Cost

[naveenoid]

All usages of "Objective" refactored to "Cost" to fit with #2639

+@sammy-tri Feature review
+@sherm1 Platform review

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This change is

[sherm1]

Whoops -- sorry, I take that back @naveenoid. Build problems, for example:

18:45:30 /home/ubuntu/workspace/experimental/9111c4bf/drake/solvers/SnoptSolver.cpp:195:47: error: no member named 'generic_objectives' in 'drake::solvers::OptimizationProblem'
18:45:30   for (auto const& binding : current_problem->generic_objectives()) {
18:45:30                              ~~~~~~~~~~~~~~~  ^
18:45:30 /home/ubuntu/workspace/experimental/9111c4bf/drake/solvers/IpoptSolver.cpp:406:42: error: no member named 'generic_objectives' in 'drake::solvers::OptimizationProblem'
18:45:30     for (auto const& binding : problem_->generic_objectives()) {
18:45:30                                ~~~~~~~~  ^
18:45:31 1 error generated.

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Review status: all files reviewed at latest revision, all discussions resolved, some commit checks pending.

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Comments from Reviewable

[naveenoid]

ready for review.

[naveenoid]

@drake-jenkins-bot retest this please

[sammy-tri]

Reviewed 6 of 6 files at r1, 2 of 2 files at r2.
Review status: all files reviewed at latest revision, 1 unresolved discussion, some commit checks pending.

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drake/solvers/NloptSolver.cpp, line 46 [r2] (raw file):

// This function meets the signature requirements for nlopt::vfunc as
// described in
// http://ab-initio.mit.edu/wiki/index.php/NLopt_C-plus-plus_Reference#ObjectCostive_function

The URL for the NLopt documentation should not change.

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Comments from Reviewable

[sammy-tri]

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Review status: 7 of 8 files reviewed at latest revision, all discussions resolved.

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drake/solvers/NloptSolver.cpp, line 46 [r2] (raw file):

Previously, sammy-tri wrote…

The URL for the NLopt documentation should not change.

Thanks!

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Comments from Reviewable

[sammy-tri]

Reviewed 1 of 1 files at r3.
Review status: all files reviewed at latest revision, all discussions resolved, some commit checks pending.

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Comments from Reviewable

[david-german-tri]

@sherm1 FYI, you can use in situations like this!

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Review status: all files reviewed at latest revision, all discussions resolved, some commit checks pending.

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Comments from Reviewable

[sherm1]

Thanks, @david-german-tri -- I'll until the build finishes.

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Review status: all files reviewed at latest revision, all discussions resolved, some commit checks pending.

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Comments from Reviewable

[sherm1]

Reviewed 2 of 2 files at r2, 1 of 1 files at r3.
Review status: all files reviewed at latest revision, all discussions resolved.

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Comments from Reviewable

[sherm1]

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Review status: all files reviewed at latest revision, all discussions resolved.

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Comments from Reviewable