Stop using Boost's tr1 regex implementation

[tomimaki]

tr1 is gone in the Boost 1.65 and later. ̶A̶d̶j̶u̶s̶t̶ ̶t̶h̶e̶ ̶c̶o̶d̶e̶ ̶b̶y̶ ̶s̶w̶i̶t̶c̶h̶i̶n̶g̶ ̶t̶o̶ ̶C̶+̶+̶1̶1̶'̶s̶ ̶r̶e̶g̶e̶x̶ ̶h̶e̶a̶d̶e̶r̶ ̶i̶n̶s̶t̶e̶a̶d̶.̶ I hope it's right solution.

[chief1983]

Probably going to have to not care about old compilers for this project, but is there a clean way to allow it to detect one or the other and support older compilers with boost instead of requiring this C++11 feature?

[tomimaki]

Maybe this will be better but I dunno how this works for old compilers. Unfortunately this will fix only 1 error, there are more errors (not related to this) that prevent from compiling.