Add PARI's idealchinese function to Sage

[mmasdeu]

This ticket adds idealchinese from PARI.

[mmasdeu]

New commits:

​12cf71a

Trac 16886: Added pari's idealchinese function.

[pbruin]

The code looks good to me. Here are just a few remarks about the documentation (sorry that this is longer than the documentation itself...):

• The first line should be a short description of what the function does.
• The usual format for documenting argument lists has -- instead of :, e.g.

  - ``x`` -- prime ideal factorization
  

• A typo: elementbb -> element b
• Use single backquotes around formulae so they are LaTeXed in the HTML and PDF documentation, and use LaTeX macros like \ge instead of >=.
• Maybe it is useful to mention the ambient number field somewhere...

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​aa6aea8

Trac 16886: fixed documentation, added one doctest.

[mmasdeu]

I fixed the patch following your comments (thanks!).