configure.ac, lib/, src/: Use _PATH_BSHELL instead of our own setting

[alejandro-colomar]

Let's respect the system default.

---

Revisions:

v1b

• Rebase

$ git rd 
1:  bd8b801fb = 1:  6848cb5b5 configure.ac, lib/, src/: Use _PATH_BSHELL instead of our own setting

v1c

• Rebase

$ git rd 
1:  6848cb5b5 = 1:  f59d7a291 configure.ac, lib/, src/: Use _PATH_BSHELL instead of our own setting

v1d

• Rebase

$ git rd 
1:  f59d7a291 = 1:  2c6c8b00d configure.ac, lib/, src/: Use _PATH_BSHELL instead of our own setting

Details

v1e

• Rebase

$ git rd 
1:  2c6c8b00d = 1:  651fa9c75 configure.ac, lib/, src/: Use _PATH_BSHELL instead of our own setting