Add -lmodes switch

Add -lmodes switch for listing the modes defined into a
many-building-profiles fobos file.
Correct my bad English in some error messages

Correct my bad English in some error messages. Thank you Tomas...
Added Tomas as contributor

Added Tomas as contributor
Added Tomas as contributor

Added Tomas as contributor
Correct README

Correct README.md: change word building "profile" with building
"mode".
Add rules to fobos for performing minor-tasks

Add the possibility to write "rules" into fobos
file for performing "minor" tasks (e.g. to
create documentation, to create project archive,
etc...).
Correct README

Correct README
Add list of modules into requirements doc

Modify documentation: add list of modules into requirements.
Fix bug on cflags and improve rules

Fix bug on defualt cflags value (it must -c but cliargs was set to
null string, fixed thanks to jacobwilliams) and improve rules in
order to execute many commands by means of a single rule.
Fix bug on fobos options overloading
Improve modes and rule of fobos file

Improve modes and rule of fobos file: add possibility to print
help message explaining the aim of modes and rules.
Corrected various grammatical errors.