Use dec number format by default

[splix]

Currently it always expect hex for all value, which is no user friendly. It should parse as hex only if it has 0x prefix.

Following should generate identical transaction value:

emerald transaction \
  0x3fd9075a076b38b3a1c6c12e77912620c07968fd \
  0x863a61ceb4694670fb0bb27da613eed60a565a0d \
  1234567890

emerald transaction \
  0x3fd9075a076b38b3a1c6c12e77912620c07968fd \
  0x863a61ceb4694670fb0bb27da613eed60a565a0d \
  0x499602d2

[splix]

That's for all parameters