Restructure cmake_options.rst

[stinebuu]

This fixes #2067.

Convert to tables, and restructure ordering.

[heplesser]

Thanks, that will be much better. I added some suggestion for organizing items a bit differently to provide an even better overview to the user.

[stinebuu]

@heplesser I think I have addressed all your comments, could you have a second look?

[heplesser]

@stinebuu Thanks a lot! Going through once again I noticed a number of further details, see below. Two general points:

• Should the entries in the left column all be typeset as code, e.g., -Dwith-python=[OFF|ON|...]?
• I think it would look tidier to put the bracket with the default into the sentence, i.e., like "Build with MPI parallelization [default: OFF]."
• I also think that the defaults are not all given in the same way, some with :, some with =, some with space.

[stinebuu]

@heplesser Thanks for your comments! I have addressed them now, please have another look.

Do you want me to also update the cmake options in CMakeLists.txt to fit with the changes in this PR?

nest-simulator/CMakeLists.txt

Lines 48 to 52 in cb61289

	set( tics_per_ms "1000.0" CACHE STRING "Specify elementary unit of time. [default 1000.0]" )
	set( tics_per_step "100" CACHE STRING "Specify resolution. [default 100]" )
	# add user modules
	set( external-modules OFF CACHE STRING "External NEST modules to be linked in, separated by ';'. [default=OFF]" )

The table widths are quite long now (at least for some of the tables), because I don't know how to cut the links over two lines (the SIONLIB link is the main problem). The width of the External libraries table is now 155 characters. For me this is okay, but I wanted to point it out just in case.

[heplesser]

@stinebuu Yes, having the same information in the CMakeLists.txt would be good. Inconsistency is irritating for users. I think the wide lines should not be a problem, they will be rendered nicely by Sphinx, I believe. @jessica-mitchell, can you confirm this?

[jessica-mitchell]

@stinebuu looks good! The large tables render fine as well :)