[R-Forge #2154] add_Series ignores 'theme'; add_TA does not support 'theme'

Submitted by: Garrett See
Assigned to: Nobody
[R-Forge link](http://r-forge.r-project.org/tracker/index.php?func=detail&aid=2154&group_id=125&atid=544)

getSymbols(c('SPY', 'DIA'), src='yahoo')
chart_Series(Cl(SPY))

thm <- chart_theme()
thm$col$line.col <- 'lightblue'
## The following should plot a lightblue line,
## but instead plots an orange line

add_Series(Cl(DIA), theme=thm, on=1)
## A workaround is to use add_TA with a 'col' argument
## (add_TA does not support the use of the 'theme' argument)

add_TA(Cl(DIA), col='green', on=1)

Reproduce the examples using chart_Series, chart_theme, add_Series, and add_TA, comparing the requested lightblue theme with the observed orange line. Trace how the theme argument is handled by add_Series and whether add_TA accepts it. Done means both entry points honor the documented theme behavior, with the examples producing the intended styling.

Written by the indexing model from the issue text.