[Proj] Build fails on Windows

[J. Luis]

Hi,

On Windows (VS2010) the build errors after the addition of the the 
healpix projection

Joaquim Luis

PJ_healpix.c(149) : error C2057: expected constant expression
PJ_healpix.c(149) : error C2466: cannot allocate an array of constant size 0
PJ_healpix.c(149) : error C2087: 'vert' : missing subscript
PJ_healpix.c(222) : warning C4048: different array subscripts : 'double 
(*)[1]' and 'double [18][18]'
PJ_healpix.c(238) : warning C4048: different array subscripts : 'double 
(*)[1]' and 'double [12][12]'
PJ_healpix.c(572) : error C2143: syntax error : missing ';' before 'type'
PJ_healpix.c(573) : error C2143: syntax error : missing ';' before 'type'
PJ_healpix.c(575) : error C2065: 'x' : undeclared identifier
PJ_healpix.c(575) : error C2065: 'y' : undeclared identifier
PJ_healpix.c(588) : error C2061: syntax error : identifier 
's_healpix_inverse'
PJ_healpix.c(588) : error C2059: syntax error : ';'
PJ_healpix.c(588) : error C2059: syntax error : 'type'
PJ_healpix.c(652) : error C2065: 's_healpix_inverse' : undeclared identifier

I also get this warnings that are independent of the above problem

pj_open_lib.c(46) : warning C4129: 'p' : unrecognized character escape 
sequence
pj_open_lib.c(46) : warning C4129: 'c' : unrecognized character escape 
sequence
pj_open_lib.c(46) : warning C4129: 'p' : unrecognized character escape 
sequence
pj_open_lib.c(46) : warning C4129: 'c' : unrecognized character escape 
sequence
pj_open_lib.c(46) : warning C4129: 'V' : unrecognized character escape 
sequence
pj_open_lib.c(46) : warning C4129: 'S' : unrecognized character escape 
sequence