require didn't allow to load a test version without specifying it.
With conda, as there is always only one version in the environment,
the version found should always be loaded (even if test version).

JIRA ICSHWI-4144 #action In Progress

Synchronize tools with e3-require

See merge request e3/require!2

Sync with tag 7.0.3.1-3.1.2/R-3.1.2-b02bfff5-1911181214

Only clean terminal when stdout is opened on a terminal
Avoid "stty: standard input: Inappropriate ioctl for device" otherwise

conda needs to update the path in some files

iocsh scripts are part of the require package.
Version is the same as require.

- LD_LIBRARY_PATH shouldn't be used (conda uses RPATH)
- E3 SITE PATH not used

We build on CentOS 6 and realpath and -g are not available on the bash
version used.

Environment variables are handled by conda activate/deactivate scripts

Use /usr/bin/env to execute the first tclsh that is in the PATH
(will be the one installed by conda).

This is the only OS we support

When using conda, we have only one version of each module in an
environment:
- Where a module is installed doesn't really matter.
We install all of them under EPICS_MODULES.
- Keep the same check as PSI to find snc (it could be simplify) but we
know the right one will be found

EPICS_BASE / EPICS_BASE_VERSION / EPICS_MODULES are set as global
environment variables by conda

selected merged from PSI 

Except driver.makefile and require.c

For newer compilers (not vxWorks 5) don't include system headers in .d files in order to avoid problems when cross-compiling for older Linux hosts

This reverts commit 14476605.

This reverts commit c6d3216a.