Add script to print build environment info. (#539)

* Add script to print build environment info.

The new script is also included in:
- all.sh
- basic-build-test.sh

* Tidy up environment reporting script.

Changes include:
- making the echo calls portable
- removing unnecessary brackets
- using more efficient checks for the existance of commands
- correcting typos and copyright year

* Update references to output_env.sh
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index a2b0995..5c18f4d 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -121,6 +121,9 @@
 #
 # Indicative running times are given for reference.
 
+msg "info: output_env.sh"
+scripts/output_env.sh
+
 msg "test: recursion.pl" # < 1s
 tests/scripts/recursion.pl library/*.c
 
diff --git a/tests/scripts/basic-build-test.sh b/tests/scripts/basic-build-test.sh
index 9fab396..9b8bd3c 100755
--- a/tests/scripts/basic-build-test.sh
+++ b/tests/scripts/basic-build-test.sh
@@ -39,6 +39,10 @@
 CONFIG_H='include/mbedtls/config.h'
 CONFIG_BAK="$CONFIG_H.bak"
 
+# Step 0 - print build environment info
+scripts/output_env.sh
+echo
+
 # Step 1 - Make and instrumented build for code coverage
 export CFLAGS=' --coverage -g3 -O0 '
 make clean