scheme interface for oblique coefs

[stevengj]

Scheme interface to #940, same as Python (optional direction keyword argument to eigenmode coefficients).

[oskooi]

The build is failing on Travis (as well as my local machine) due to a SWIG-related error:

meep-meep_wrap.o: In function `_wrap_do_get_eigenmode_coefficients(scm_unused_struct*, scm_unused_struct*, scm_unused_struct*, scm_unused_struct*, scm_unused_struct*, scm_unused_struct*, scm_unused_struct*, scm_unused_struct*, scm_unused_struct*, scm_unused_struct*)':
meep_wrap.cxx:(.text+0x43f95): undefined reference to `do_get_eigenmode_coefficients(meep::fields*, meep::dft_flux, meep::volume const&, int*, int, int, std::complex<double>*, double*, double, double, meep::vec (*)(double, int, void*), void*)'
collect2: error: ld returned 1 exit status
Makefile:517: recipe for target 'meep' failed
make[3]: *** [meep] Error 1

Fix: update the SWIG wrapper?

[stevengj]

Should be fixed now.

[oskooi]

This PR has broken the backward compatibility of the get-eigenmode-coefficients routine such that any of the scheme/example files such as binary-grating.ctl or metasurface_lens_phasemap.ctl which involve the calling convention e.g. (get-eigenmode-coefficients mode-mon (arith-sequence 1 1 nmode) #:eig-parity (+ ODD-Z EVEN-Y)) produce the following error:

Backtrace:
In ice-9/boot-9.scm:
 160: 8 [catch #t #<catch-closure 55dacae32680> ...]
In unknown file:
   ?: 7 [apply-smob/1 #<catch-closure 55dacae32680>]
In ice-9/eval.scm:
 432: 6 [eval # #]
 432: 5 [eval # #]
In unknown file:
   ?: 4 [primitive-load "binary_grating.ctl"]
In ice-9/eval.scm:
 453: 3 [eval # ()]
 432: 2 [eval # #]
 436: 1 [eval # #]
In unknown file:
   ?: 0 [do-get-eigenmode-coefficients # # # ...]

ERROR: In procedure do-get-eigenmode-coefficients:
ERROR: Wrong number of arguments to do-get-eigenmode-coefficients

[stevengj]

Whoops, I forgot to pass the extra arg to do-get-eigenmode-coefficients … should be fixed now?