v1.5.6

features

• helper methods to create integer lists (#1179)
• default of --benchmark_filter is now rather than "." (#1207)

fixes

• type warning (#1193)
• returning a reference when callers want pointers (65dc63b)

cleanup

• remove dead code from PredictNumItersNeeded (#1206)
• fix clang-tidy warnings (#1195) and typos (#1194)
• prefix macros (#1186) and flags (#1187, #1185) to avoid name clashes
• downgrade warnings for googletest (twice) (#1203, 560b0834, ee726a7)