Support for bootstrap-based CI's

[philipdelff]

Curently, RSE and CI's are derived from a covariance step. addParameterTable() actually only works if there is a successful cov step. Support for these situations needed:

• no cov, no bootstrap
• cov, no bootstrap (currently assumed)
• cov and bootstrap (choose between them or even show some info side by side)
• only bootstrap

Should support bootstrap results from PSN as well as BBR.

I have started the work in the "bootstrap" branch.

[bmreilly]

After using this function, it works great!

One feature request: Make the title for the 95% CI from bootstrap Bootstrap 95% CI or put a note marker like \\ddag on the column title for the 95% CI and add a footnote stating that the 95% CI is derived from a bootstrap.