Problem: <use /> depends_on places dependencies realtive to first
element of recursion

Solution: Added dependent to depends_on on method to ensure the
dependency order.
Merge pull request #49 from sappo/master

Problem: <use /> depends_on places dependencies realtive to first element of recursion
Problem: it's annoying to write CI systems by hand
Solution: generate .travis.yml and ci_build.sh if no CI system exists
Incidental: sort inner gsl scripts in manifests by name
Resolves #46
Merge pull request #50 from jemc/master

Problem: it's annoying to write CI systems by hand
Problem: Readme is written in pure markdown
Solution: Use gitdown to generate markdown readme.
Problem: Typos, wrong information and huge toc
Solution: fix typos, add correct information and shrink toc
Problem: Wrong grammar
Solution: fix grammar
Merge pull request #51 from sappo/master

Problem: Readme is inconsitent with explanations in project.xml
Problem: it's painful to make new .gitignore by hand

Solution: generate this first time

Fixes #45
Problem: need way to specify model script

Solution: add 'script' property; if this is set then generate
appropriate gsl line. Note: we set -topdir:.. so the script works
from within src. (E.g. Java generates into ../main not into src).

Fixes #42
Merge pull request #52 from hintjens/master

Problem: it's painful to make new .gitignore by hand
get additional params from nested param elements.
Merge pull request #53 from mknoszlig/master

Problem: can't freely specify additional model parameters in project.xml
Problem: resolve_dependency always warns for custom 'use' in project
Solution: only warn if the required properties are not defined
Incidental: Use "template 0" in zproject_projects.gsl for easier editing
Problem: no newline at end of file
Solution: add newline
Problem: Too difficult to keep warning headers consistent.
Solution: Reference a variable which holds the warning header string
Problem: No builtin way to valgrind or gdb
Solution: Add 'make memcheck' and 'make debug' to automake
Problem: `make memcheck` gives exit code 0 even on failure
Solution: use `--error-exitcode=1` to fail with nonzero exit status
Problem: `make memcheck` and `make debug` do not trigger rebuild
Solution: add automake dependency on selftest libtool wrapper
Problem: Default ci_build.sh does not include memcheck
Solution: Add make memcheck to ci_build.sh