Making object navigation more bash-like

[kpgriesser]

The current object navigation is a 'one-step-at-a-time' approach for stepping into and out of object map hierarchy layers. Consider a simple case of a 3-dimensional simple array.

()   # top
 \
  +- c0  # component
     \
      +- function0 # sub-component slot
            \
             + v_xyz # unsigned[3][5][7]

Here is an example session ( available in git@github.com:tactcomplabs/sst-ext-tests.git devel branch):

$ cd tests/core-debug
$ sst --interactive-start=0 omni.py -- --function0=dbgsst15.OMArrays

# Hey Billy, can you tell me what's in v_xyz[2][4][6] and v_xyz[1][2][3]?
# Sure Pop! Give me a few minutes and I'll get back to you

> confirm false
> cd c0
> cd function0
> cd v_xyz
> pwd
> cd 2
> cd 4
> pwd
c0/function0/v_xyz/2/4 (double [7])

> ls
0/ (double [5][7])
1/ (double [5][7])
2/ (double [5][7])

> cd 2
> ls
0/ (double [7])
1/ (double [7])
2/ (double [7])
3/ (double [7])
4/ (double [7])

> cd 4
> pwd
c0/function0/v_xyz/2/4 (double [7])

> ls
0 = 99.00000000000000000 (double)
1 = 100.00000000000000000 (double)
2 = 101.00000000000000000 (double)
3 = 102.00000000000000000 (double)
4 = 103.00000000000000000 (double)
5 = 104.00000000000000000 (double)
6 = 105.00000000000000000 (double)

> cd ..
> cd ..
> pwd
c0/function0/v_xyz (double [3][5][7])

> cd 1
> cd 2
> pwd
c0/function0/v_xyz/1/2 (double [7])
> ls
0 = 50.00000000000000000 (double)
1 = 51.00000000000000000 (double)
2 = 52.00000000000000000 (double)
3 = 53.00000000000000000 (double)
4 = 54.00000000000000000 (double)
5 = 55.00000000000000000 (double)
6 = 56.00000000000000000 (double)

# It's 105 and 53...I think...  oh wait, let me go back and check!

Part 1: The basic chdir/cd requirements

1. Provide symbol / to represent the top level instead of ()

2. Allow long path strings to be specified in the cd command (other commands can follow)
   example: cd c0/function0/v_xyz/2/4 ( this should support tabed auto-completion )

3. Allow for use of . and .. to be used in the relative path.
   example: `cd ../1/4

4. Allow for absolute paths from the top level
   example cd /c0/function0/v_xyz/2/4

Note: See SimpleDebugger::cd_name_stack which navigates us to our last position when we re-enter inter
active mode. This feature is intended to refresh the objmap which is not needed for simple navigation.

Part 2: Building a better UI

Once we have the ability to specify paths, we can create our own user directory stack, just like in bash. To support this, we should add the commands:

 `pushd`, `popd`, and `dirs`

Part 3: Testing

Please add tests to sst-ext-tests/tests-core-debug of the form cd_*.sh using a current example like type-arrays.sh.