Updated some external in user docs.
merged from paulette
Merge pull request #1869 from naylor-b/docs

doc changes from paulette
Merge branch 'mpi' of github.com:Kenneth-T-Moore/OpenMDAO-Framework into mpi
Merge branch 'mpi' of github.com:naylor-b/OpenMDAO-Framework into mpi
Speedup for adjoint Linear GS
Merge pull request #1870 from Kenneth-T-Moore/mpi

Speedup for adjoint Linear GS
Added check for unintialized variables that are flattenable, sources of a connection, part of an active SimpleSystem and would increase the size of the global array.
Created new design doc outline and added files. Hid it between glossary and index.
Merge pull request #1872 from pziegfeld/design-docs

Created new design doc outline and added files. Hid it between glossary and index.
Added more tests for uninintialzed arrays.
Added more tests for uninintialzed arrays.
Refactored test.
Merge branch 'dev' of https://github.com/OpenMDAO/OpenMDAO-Framework into uninit-array-error
Changed check in CompoundSystem.setup_scatters to prevent numpy from generating FutureWarning.
Merge pull request #1871 from crobinsonut/uninit-array-error

Raise error for uninitialized variables
fixed an issue with system.dump
Merge branch 'dev' of github.com:OpenMDAO/OpenMDAO-Framework into mpi