API doxygen scrub

[skliper]

Is your feature request related to a problem? Please describe.
Doxygen documentation out of date

Describe the solution you'd like
Format/layout changes:

• Table-fy return values (and eliminate some pdf build errors/warnings)
• Make links from text where appropriate
• Documented OSAL return codes
• Add parameter direction where missing
• Added explicit grouping where appropriate (and group references)
  • Group API's and reference from main page
• Marked OS_TaskRegister as deprecated in documentation (no code change yet, that's Wrap OS_TaskRegister in OMIT_DEPRECATED define #255)
• Marked exception handling as deprecated in doc (code change is Remove FPU and exception handling APIs from OSAL #366)
• Marked shmem as deprecated in doc (code change is OSAL headers define a shared memory API that is not actually implemented anywhere #18)
• Added missing descriptions and parameter definitions
• Added clock address rounding comments related to Microsecond round up code doesn't round up. #12 (partial resolution)
• Delete old OSAL API doc and pdf

Information changes:

• Internal file descriptor not accessible (recommend against mixing direct calls with osal APIs)
• Noted OS_TranslatePath is available to use with open directly by an app

Describe alternatives you've considered
None

Additional context
Related issues: #116, #70 , #10
Partial: #255, #12 , #18, #366

Requester Info
Full name and company/organization if applicable