MAINT: remove usage of exec_command in config.py
MAINT: remove usage of exec_command in config.py

* replace usage of exec_command() with standard
library equivalent in the distutils config
module

jakirkham/numpy,pizzathief/numpy,seberg/numpy,pbrod/numpy,WarrenWeckesser/numpy,simongibbons/numpy,abalkin/numpy,shoyer/numpy,numpy/numpy,pizzathief/numpy,mattip/numpy,jorisvandenbossche/numpy,jakirkham/numpy,MSeifert04/numpy,shoyer/numpy,mattip/numpy,ahaldane/numpy,anntzer/numpy,seberg/numpy,ahaldane/numpy,pizzathief/numpy,gfyoung/numpy,rgommers/numpy,simongibbons/numpy,numpy/numpy,ahaldane/numpy,MSeifert04/numpy,charris/numpy,charris/numpy,abalkin/numpy,shoyer/numpy,anntzer/numpy,pdebuyl/numpy,gfyoung/numpy,madphysicist/numpy,anntzer/numpy,grlee77/numpy,pdebuyl/numpy,charris/numpy,madphysicist/numpy,numpy/numpy,seberg/numpy,numpy/numpy,grlee77/numpy,gfyoung/numpy,MSeifert04/numpy,mattip/numpy,grlee77/numpy,WarrenWeckesser/numpy,simongibbons/numpy,WarrenWeckesser/numpy,pbrod/numpy,pbrod/numpy,mhvk/numpy,pizzathief/numpy,pbrod/numpy,simongibbons/numpy,rgommers/numpy,charris/numpy,WarrenWeckesser/numpy,madphysicist/numpy,ahaldane/numpy,endolith/numpy,mhvk/numpy,pdebuyl/numpy,jorisvandenbossche/numpy,grlee77/numpy,abalkin/numpy,mattip/numpy,MSeifert04/numpy,seberg/numpy,pbrod/numpy,mhvk/numpy,jorisvandenbossche/numpy,jorisvandenbossche/numpy,MSeifert04/numpy,grlee77/numpy,shoyer/numpy,jorisvandenbossche/numpy,endolith/numpy,shoyer/numpy,ahaldane/numpy,madphysicist/numpy,anntzer/numpy,rgommers/numpy,pizzathief/numpy,WarrenWeckesser/numpy,jakirkham/numpy,pdebuyl/numpy,endolith/numpy,simongibbons/numpy,mhvk/numpy,jakirkham/numpy,mhvk/numpy,endolith/numpy,jakirkham/numpy,madphysicist/numpy,rgommers/numpy