adding option set_as_scalar to parameters

This adds the additional member function to set the dim vec as a
scalar.

Change-Id: I0c12b4bc217b3c8b676983a9d0bd63bf20e7d8ac
document new set_as_scalar field

Change-Id: Iec769a7bbc611952904669b6ca624d9b64d6d8e6
Convert all public SetRadius methods to use set_as_scalar field.

Change-Id: I1571ce0cb14f1a8a0e530f53aa0d3d46ac1e7b68
Using set_as_scalar to add new methods to filters

Change-Id: I4b429d1e97c324ac8f567282bae63ba9ca648462
Adding set as scalar to image sources too

Change-Id: I9bf306515736d134c357c8ff12fbe91456e121be
Merge branch 'master' into SIMPLEITK-440_AddScalarSetFordim_vec

Change-Id: Ie41de1667e426061960750d8ebfdc23463550c74
Removing std::vector from dim_vec types

Change-Id: Ib3752bc0e5e154372ff2105586fde6961f698227
renamed ImageParametersWithDefaults to MemberParameters

incorrect name was used for template component

Change-Id: I4996f47bb1ddedc6756a99c2e25087c5d528b10f
Automatically add std::vector to the parameters of dim_vec

Change-Id: I79879187008770c18091718babc379fcfe94d43a
Use MemberParameters in MultiInput template component

Change-Id: Ie09bc6b44c7191befe8a5fd880e8d1977b354434
Re-factored common base methods to ProcessObject base

Created new base class for ImageFilters to contain common methods such
as setting the number of threads, debugging, and call-backs/commands.

Change-Id: I2902c55a03d6ad73f3fb08b491637b454f1aa504
Add ProcessObject number of threads parameter

Change-Id: I061c07345e05923e29273a1ff4242818e8dfdcfd
Export  SimpleITK_BUILD_DISTRIBUTE and python threads

Add as advanced cmake variables  SimpleITK_BUILD_DISTRIBUTE and
SimpleITK_PYTHON_THREADS.

Change-Id: I0f805f6390f1a0f4c0aab4cbb30fc25992b16c6b
COMP: remove header which doesn't exist

Change-Id: Icb5530e9c88021ad10b2ae757e0b116a6f8a3d6e
COMP: remove additional header for non-existent file

Change-Id: I2f5ab446a07d7217299cfa2a19ee9734bb11aca9
Changed dim_vec test parameters to use json array

The test generator scripts are updated to iterate over the json
array, but still prefer the language override.

Change-Id: Ie3e369c47d042d0e29ec57cffbf2c43264f7a1ed
adding missing iostream header

Change-Id: Ieed2d759672b8170d53b97fcddaa947acdad0565
Adding DiscreteGaussianDeriativeImageFilter

Change-Id: Id7134fa343ed1ea4b13e4089adbfd535863a86ad
Adding tests for DiscreteGaussianDerivative filter

Change-Id: Id25990ca6cb437c3e2515941a5e9d8217eb8fa15
COMP: Fix unsigned warning in test

Change-Id: I162ece263afa40fa8fd8951d8941b21888b0d9e7