Added 'eps' in optimize.show_options for L-BFGS-B

In scipy.optimize.minimize, when algorithm is L-BFGS-B, there is an
option called eps. However, this options is missing if we use
scipy.optimize.show_options('minimize', 'L-BFGS-B') to look up its
options.
Merge pull request #3427 from yw5aj/master

Added 'eps' in scipy.optimize.show_options for L-BFGS-B
MAINT: Add myself to thanks :)

I worked on scipy.sparse a bit last summer for GSoC.
Thanks again @pv!
Merge pull request #3428 from cowlicks/thanks

MAINT: Add myself to thanks :)
MAINT: tweak cython variables declarations to avoid the warning
'Non-trivial type declarators in shared declaration ...' that is
generated by cython 0.20.
MAINT: special: tweak the generated cython variable declarations in _ufuncs.pyx
to avoid the warning 'Non-trivial type declarators in shared declaration ...'
that is generated by cython 0.20.
GEN: special: regenerate _ufuncs.pyx
BUG: Correcting the normalization of chebwin window function
Merge pull request #3433 from ankit-maverick/chebwin

Correcting the normalization of chebwin window function
Merge pull request #3430 from WarrenWeckesser/cython-declarations

MAINT: Fix some cython variable declarations to avoid warnings with cython 0.20.
ENH: add the limit shape c=0 to genpareto distribution

For c=0, genpareto is equivalent to the exponential
distribution.
BUG: use special.log1p instead of np.log1p

np.log1p(np.inf) is reported to produce nans on some platforms,
see numpy issue gh-4225
BUG: use scipy.special.expm1 instead of np.expm1
ENH: vectorize genpareto._munp

implementation is by @pbrod
BUG: special-case genpareto(c=-1)