scheme: Add guard and parameterize

[okuoku]

• SRFI-34 + raise-continuable
• error predicates, at least for R7RS defined procedures
• SRFI-39

No dynamic-wind support. Stick with guard.

EDIT:

Reduced requirement to

• guard
• raise
• make-parameter 1-arg only (for Chez compatibility)
• parameterize

[okuoku]

Guard:

--
-- Summary:
--
--     OK : DIGAMMA
--     OK : GUILE3
--     OK : SAGITTARIUS
--     OK : CHIBI_SCHEME
--     OK : CHICKEN5_CSI
--     ERR: ICYC
--     OK : FOMENT
--     OK : GOSH
--     OK : KAWA
--     OK : CHEZ_SCHEME
--     OK : GUILE
--     OK : IRON_SCHEME
--     OK : RACKET
--     ERR: BIGLOO
--     ERR: GSI
--     OK : MIT_SCHEME
--     ERR: S7
--     ERR: SCM
--     OK : STKLOS

Cyclone: #151
Gambit: Lacks raise-continuable
Bigloo, s7, SCM: Needs to implement our own.

[okuoku]

Parameters:

--
-- Summary:
--
--     OK : DIGAMMA
--     OK : GUILE3
--     OK : SAGITTARIUS
--     OK : CHIBI_SCHEME
--     OK : CHICKEN5_CSI
--     ERR: ICYC
--     OK : FOMENT
--     OK : GOSH
--     OK : KAWA
--     OK : CHEZ_SCHEME
--     OK : GUILE
--     OK : IRON_SCHEME
--     OK : RACKET
--     ERR: BIGLOO
--     OK : GSI
--     OK : MIT_SCHEME
--     OK : S7
--     ERR: SCM
--     OK : STKLOS

Cyclone: Bug
Bigloo, SCM: Needs import

raise-continuable and with-exception-handler is useless on environment without call/cc .

[okuoku]

Split bugs: #151 #152 #153

Done: 5c20b2e