splitting log10 tests out of test/agrad/agrad_test.cpp
splitting log10 tests out of test/agrad/agrad_test.cpp

stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/stan,stan-dev/math,stan-dev/math,stan-dev/math,stan-dev/stan,stan-dev/stan,stan-dev/stan,stan-dev/stan