Fix types

[emmt]

• fix integer types (Int32 --> Cint) and double check the prototypes in fitsio.h header
• fix wrong type in fits_get_rowsize/ffgrsz
• ffhdr2str returns a Cint not a Ptr{Ptr{Uint8}}
• fits_get_img_size/ffgisz and fits_create_img/ffcrim: argument naxes is an array of long's
• use ffcrimll for fits_create_img and ffppxll for fits_write_pix instead of ffcrim and ffppx to let the user call these methods with any vector of integers (and save him/her the bothering of doing any conversion)
• in fits_read_col and fits_write_col no needs to convert to Int64, this is automatically done by ccall
• enlarge the accepted types for arguments of the methods (e.g. keynum::Int --> keynum::Integer in fits_read_record), ccall does the conversion
• use @eval macro to create data type tables and related methods, also added the table summarizing the assumptions about what types should be used (for future reference, maybe it can be in the documentation instead) missing table types 40 and 41 were added (for C unsigned long and C long) for now some methods may override another one (but this is is harmful, can be avoided later when building the dictionary of FITS table type code to Julia types which is needed to read table columns)

[coveralls]

Coverage decreased (-4.47%) to 57.18% when pulling c87e835b0f2d9e88dde85e00129f07f7436e435a on emmt:pull-request/c87e835b into 3001911efef010c799eee125f484082ba8d3e5a2 on JuliaAstro:master.

[kbarbary]

Other than my comment about a missing nelements this all looks good to merge.